diff --git a/.githooks/data_external/example_import_tfvars_via_extractor.py b/.githooks/data_external/example_import_tfvars_via_extractor.py
deleted file mode 100644
index 84874bf6..00000000
--- a/.githooks/data_external/example_import_tfvars_via_extractor.py
+++ /dev/null
@@ -1,61 +0,0 @@
-#!/usr/bin/env python3
-import os
-import json
-import sys
-from types import SimpleNamespace
-from typing import List
-
-sys.dont_write_bytecode = True
-
-# NOTE! This part is a bit convoluted but there's a method to the madness:
-# - Script executes from `/~/cx-field-tools-installer`. 
-# - Need to change dir into .githooks (to avoid the `.` import problem), import, then return to project root so the extractor can find tfvars.
-# - Error this is solving: `ImportError: attempted relative import with no known parent package``
-project_root = os.getcwd()
-os.chdir(f"{project_root}/.githooks")
-sys.path.append(".")
-from utils.extractors import get_tfvars_as_json #convert_tfvars_to_dictionary
-
-# Extract tfvars just like we do with the Python validation script
-os.chdir(project_root)
-data_dictionary = get_tfvars_as_json()
-data = SimpleNamespace(**data_dictionary)
-
-# Connection string modifiers
-mysql8_connstring = "allowPublicKeyRetrieval=true&useSSL=false"
-v24plus_connstring = "permitMysqlScheme=true"
-
-
-def return_tf_payload(status: str, value: str):
-    payload = {'status': status, 'value': value}
-    print(json.dumps(payload))
-
-
-def generate_connection_string(mysql8: str, v24plus: str):
-    connection_string = ""
-    add_mysql8 = False
-    add_v24plus = False
-
-    if mysql8.startswith("8."): 
-        add_mysql8 = True
-
-    if v24plus >= "v24":
-        add_v24plus = True
-
-    if add_mysql8 and add_v24plus:
-        connection_string = f"?{mysql8_connstring}&{v24plus_connstring}"
-    elif add_mysql8 and not add_v24plus:
-        connection_string = f"?{mysql8_connstring}"
-    elif not add_mysql8 and add_v24plus:
-        connection_string = f"?{v24plus_connstring}"
-
-    return connection_string
-
-
-if data.flag_use_container_db:
-    connection_string = generate_connection_string(data.db_container_engine_version, data.tower_container_version)
-else:
-    connection_string = generate_connection_string(data.db_engine_version, data.tower_container_version)
-
-return_tf_payload("0", connection_string)
-exit(0)
\ No newline at end of file
diff --git a/.githooks/data_external/generate_db_connection_string.py b/.githooks/data_external/generate_db_connection_string.py
index 882e528e..00a8646c 100644
--- a/.githooks/data_external/generate_db_connection_string.py
+++ b/.githooks/data_external/generate_db_connection_string.py
@@ -3,13 +3,35 @@
 import json
 import sys
 from types import SimpleNamespace
-from typing import List
 
 sys.dont_write_bytecode = True
 
+
+## ------------------------------------------------------------------------------------
+## Extract TFvars and get query values
+## ------------------------------------------------------------------------------------
+# NOTE! This part is a bit convoluted but there's a method to the madness:
+#   - Script executes from `~/cx-field-tools-installer`. 
+#   - Change into .githooks (to avoid the `.` import problem), import, return to project root to extract tfvars.
+#   - Error thrown without workaround: `ImportError: attempted relative import with no known parent package`
+#   - Query object to receive objects via TF data call (i.e. resources)
+project_root = os.getcwd()
+os.chdir(f"{project_root}/.githooks")
+sys.path.append(".")
+
+from utils.extractors import get_tfvars_as_json #convert_tfvars_to_dictionary
+from utils.logger import external_logger
+from utils.common_data_external_functions import getDVal, return_tf_payload
+
+os.chdir(project_root)
+data_dictionary = get_tfvars_as_json()
+data = SimpleNamespace(**data_dictionary)
+
 # Much simpler way to get variable passed in (via Terraform sending to stdin)
 query = json.load(sys.stdin)
-data = SimpleNamespace(**query)
+# query = SimpleNamespace(**query)
+## ------------------------------------------------------------------------------------
+
 
 # Get engine_version depending on whether container DB or RDS instance is in play
 engine_version = data.db_container_engine_version if data.flag_use_container_db else data.db_engine_version
@@ -19,21 +41,11 @@
 v24plus_connstring = "permitMysqlScheme=true"
 
 
-def return_tf_payload(status: str, value: str):
-    payload = {'status': status, 'value': value}
-    print(json.dumps(payload))
-
-
 def generate_connection_string(mysql8: str, v24plus: str):
     connection_string = ""
-    add_mysql8 = False
-    add_v24plus = False
 
-    if mysql8.startswith("8."): 
-        add_mysql8 = True
-
-    if v24plus >= "v24":
-        add_v24plus = True
+    add_mysql8 = True if mysql8.startswith("8.") else False
+    add_v24plus = True if v24plus >= "v24" else False
 
     if add_mysql8 and add_v24plus:
         connection_string = f"?{mysql8_connstring}&{v24plus_connstring}"
@@ -42,11 +54,13 @@ def generate_connection_string(mysql8: str, v24plus: str):
     elif not add_mysql8 and add_v24plus:
         connection_string = f"?{v24plus_connstring}"
 
-    return connection_string
+    values = {
+        "connection_string": connection_string
+    }
+
+    return values
 
 
 if __name__ == '__main__':
-    connection_string = generate_connection_string(engine_version, data.tower_container_version)
-    return_tf_payload("0", connection_string)
-    
-    exit(0)
\ No newline at end of file
+    values = generate_connection_string(engine_version, data.tower_container_version)
+    return_tf_payload("0", values)
\ No newline at end of file
diff --git a/.githooks/data_external/generate_dns_values.py b/.githooks/data_external/generate_dns_values.py
new file mode 100644
index 00000000..9dc2b1c8
--- /dev/null
+++ b/.githooks/data_external/generate_dns_values.py
@@ -0,0 +1,84 @@
+#!/usr/bin/env python3
+import os
+import json
+import sys
+from types import SimpleNamespace
+
+sys.dont_write_bytecode = True
+
+
+## ------------------------------------------------------------------------------------
+## Extract TFvars and get query values
+## ------------------------------------------------------------------------------------
+# NOTE! This part is a bit convoluted but there's a method to the madness:
+#   - Script executes from `~/cx-field-tools-installer`. 
+#   - Change into .githooks (to avoid the `.` import problem), import, return to project root to extract tfvars.
+#   - Error thrown without workaround: `ImportError: attempted relative import with no known parent package`
+#   - Query object to receive objects via TF data call (i.e. resources)
+project_root = os.getcwd()
+os.chdir(f"{project_root}/.githooks")
+sys.path.append(".")
+
+from utils.extractors import get_tfvars_as_json #convert_tfvars_to_dictionary
+from utils.logger import external_logger
+from utils.common_data_external_functions import getDVal, return_tf_payload
+
+os.chdir(project_root)
+data_dictionary = get_tfvars_as_json()
+data = SimpleNamespace(**data_dictionary)
+
+# Much simpler way to get variable passed in (via Terraform sending to stdin)
+query = json.load(sys.stdin)
+# query = SimpleNamespace(**query)
+## ------------------------------------------------------------------------------------
+
+
+# Vars
+dns_zone_mappings = {
+    "flag_create_route53_private_zone":             ("zone_private_new",        [0, 'id']),
+    "flag_use_existing_route53_private_zone":       ("zone_private_existing",   [0, 'id']),
+    "flag_use_existing_route53_public_zone":        ("zone_public_existing",    [0, 'id']),
+}
+
+# Transformed dictionary nested into flat dicionary so value can be passed around.
+# I don't love this approach but can't find a cleaner/simpler way right now.
+dns_instance_ip_mappings = {
+    "flag_make_instance_private":                   ("tower_host_instance", ['private_ip']),
+    "flag_make_instance_private_behind_public_alb": ("tower_host_instance", ['private_ip']),
+    "flag_private_tower_without_eice":              ("tower_host_instance", ['private_ip']),
+    "flag_make_instance_public":                    ("tower_host_eip",      [0, 'public_ip'])
+}
+
+
+def populate_values(query):
+
+    external_logger.debug(f"Query is: {query}")
+
+    # Baseline variables
+    dns_zone_id = ""
+    dns_instance_ip = ""
+
+    for k,v in dns_zone_mappings.items():
+        external_logger.debug(f"k is : {k}; and v is: {v}")
+        tf_obj, dpath = v
+        tf_obj_json = json.loads(query[tf_obj])
+        dns_zone_id = getDVal(tf_obj_json, dpath) if data_dictionary[k] else dns_instance_ip
+
+
+    for k,v in dns_instance_ip_mappings.items():
+        '''`aws_instance.ec2.private_ip` vs `aws_eip.towerhost[0].public_ip`'''
+        tf_obj, dpath = v
+        tf_obj_json = json.loads(query[tf_obj])
+        dns_instance_ip = getDVal(tf_obj_json, dpath) if data_dictionary[k] else dns_instance_ip
+
+    values = {
+        "dns_zone_id": dns_zone_id,
+        "dns_instance_ip": dns_instance_ip
+    }
+
+    return values
+
+
+if __name__ == '__main__':
+    values = populate_values(query)
+    return_tf_payload("0", values)
\ No newline at end of file
diff --git a/.githooks/data_external/generate_flags.py b/.githooks/data_external/generate_flags.py
new file mode 100644
index 00000000..f95c6923
--- /dev/null
+++ b/.githooks/data_external/generate_flags.py
@@ -0,0 +1,54 @@
+#!/usr/bin/env python3
+import os
+import json
+import sys
+from types import SimpleNamespace
+
+sys.dont_write_bytecode = True
+
+
+## ------------------------------------------------------------------------------------
+## Extract TFvars and get query values
+## ------------------------------------------------------------------------------------
+# NOTE! This part is a bit convoluted but there's a method to the madness:
+#   - Script executes from `~/cx-field-tools-installer`. 
+#   - Change into .githooks (to avoid the `.` import problem), import, return to project root to extract tfvars.
+#   - Error thrown without workaround: `ImportError: attempted relative import with no known parent package`
+#   - Query object to receive objects via TF data call (i.e. resources)
+project_root = os.getcwd()
+os.chdir(f"{project_root}/.githooks")
+sys.path.append(".")
+
+from utils.extractors import get_tfvars_as_json #convert_tfvars_to_dictionary
+from utils.logger import external_logger
+from utils.common_data_external_functions import getDVal, return_tf_payload
+
+os.chdir(project_root)
+data_dictionary = get_tfvars_as_json()
+data = SimpleNamespace(**data_dictionary)
+
+# Much simpler way to get variable passed in (via Terraform sending to stdin)
+query = json.load(sys.stdin)
+# query = SimpleNamespace(**query)
+## ------------------------------------------------------------------------------------
+
+
+def populate_values(query):
+
+    external_logger.debug(f"Query is: {query}")
+
+    # Determine kinda of DNS record to create
+    dns_create_alb_record = True if (data.flag_create_load_balancer and not data.flag_create_hosts_file_entry) else False
+    dns_create_ec2_record = True if (not data.flag_create_load_balancer and not data.flag_create_hosts_file_entry) else False
+
+    values = {
+        "dns_create_alb_record": dns_create_alb_record,
+        "dns_create_ec2_record": dns_create_ec2_record,
+    }
+
+    return values
+
+
+if __name__ == '__main__':
+    values = populate_values(query)
+    return_tf_payload("0", values)
\ No newline at end of file
diff --git a/.githooks/data_external/template_get_tfvars_and_query.py b/.githooks/data_external/template_get_tfvars_and_query.py
new file mode 100644
index 00000000..b40fd0a6
--- /dev/null
+++ b/.githooks/data_external/template_get_tfvars_and_query.py
@@ -0,0 +1,52 @@
+#!/usr/bin/env python3
+import os
+import json
+import sys
+from types import SimpleNamespace
+
+sys.dont_write_bytecode = True
+
+
+## ------------------------------------------------------------------------------------
+## Extract TFvars and get query values
+## ------------------------------------------------------------------------------------
+# NOTE! This part is a bit convoluted but there's a method to the madness:
+#   - Script executes from `~/cx-field-tools-installer`. 
+#   - Change into .githooks (to avoid the `.` import problem), import, return to project root to extract tfvars.
+#   - Error thrown without workaround: `ImportError: attempted relative import with no known parent package`
+#   - Query object to receive objects via TF data call (i.e. resources)
+project_root = os.getcwd()
+os.chdir(f"{project_root}/.githooks")
+sys.path.append(".")
+
+from utils.extractors import get_tfvars_as_json #convert_tfvars_to_dictionary
+from utils.logger import external_logger
+from utils.common_data_external_functions import getDVal, return_tf_payload
+
+os.chdir(project_root)
+data_dictionary = get_tfvars_as_json()
+data = SimpleNamespace(**data_dictionary)
+
+# Much simpler way to get variable passed in (via Terraform sending to stdin)
+query = json.load(sys.stdin)
+# query = SimpleNamespace(**query)
+## ------------------------------------------------------------------------------------
+
+
+def populate_values(query):
+
+    external_logger.debug(f"Query is: {query}")
+
+    # Add logic here
+
+    values = {
+        "key": "value"
+    }
+
+    return values
+
+
+if __name__ == '__main__':
+    values = populate_values(query)
+    return_tf_payload("0", values)
+
diff --git a/.githooks/utils/common_data_external_functions.py b/.githooks/utils/common_data_external_functions.py
new file mode 100644
index 00000000..569f9b23
--- /dev/null
+++ b/.githooks/utils/common_data_external_functions.py
@@ -0,0 +1,45 @@
+# Centralizes common functions which will be needed across scripts called by TF `data.external`.
+import json
+from typing import Any
+
+from utils.logger import external_logger
+
+
+# https://www.reddit.com/r/learnpython/comments/y02net/is_there_a_better_way_to_store_full_dictionary/
+def getDVal(d : dict, listPath : list) -> Any:
+    '''
+    Recursively loop through a dictionary object to get to the target nested key.
+    This allows us to specify a TF objecy and the exact subpath to slice from.
+    Note: The path must be defined as discrete elements in a list.
+    '''
+    for key in listPath:
+        d = d[key]
+    return d
+
+
+def convert_booleans_to_strings(payload: dict) -> dict: 
+    '''
+    TF data.external freaks out if JSON true/false values not returned as strings.
+    Unfortunately, json.dumps will convert True/False to true/false, but not turn to string.
+    This function fixes the json.dumps payload so it's acceptable to TF.
+    '''
+    for k,v in payload.items():
+        external_logger.debug(f"k is {k} and v is {v}.")
+        if isinstance(v, bool):
+            payload[k] = "true" if v == True else "false"
+    return payload
+
+
+def return_tf_payload(status: str, values: dict):
+    '''
+    Package the payload to return to TF data.external.
+    Note: Using external_logger due to the stdout/stderr problem.
+    '''
+    external_logger.debug(f"Payload is: {values}")
+
+    payload = {'status': status, **values}
+    payload = convert_booleans_to_strings(payload)
+    print(json.dumps(payload))
+
+    external_logger.error("Flushing.")
+    exit(0)
\ No newline at end of file
diff --git a/.githooks/utils/extractors.py b/.githooks/utils/extractors.py
index 37234e8b..88ae5699 100644
--- a/.githooks/utils/extractors.py
+++ b/.githooks/utils/extractors.py
@@ -65,7 +65,8 @@ def convert_tfvars_to_dictionary(file):
             elif flag_skip_block_comment:
                 indices_to_pop.append(i)
 
-        logger.debug(f"Indices to pop: {indices_to_pop}")
+        # This breaks my `external.data` implementation when logging set to debug. Commenting out.
+        # logger.debug(f"Indices to pop: {indices_to_pop}")
         purge_indices_in_reverse(indices_to_pop)
 
 
diff --git a/.githooks/utils/logger.py b/.githooks/utils/logger.py
index df7efbdd..73feec0a 100644
--- a/.githooks/utils/logger.py
+++ b/.githooks/utils/logger.py
@@ -1,17 +1,52 @@
 
 import logging
+import logging.handlers
 import sys
 
-file_handler = logging.FileHandler(filename='tmp.log')
-stdout_handler = logging.StreamHandler(stream=sys.stdout)
-handlers = [file_handler, stdout_handler]
 
-logging.basicConfig(
-    level=logging.INFO, 
-    # format='[%(asctime)s] {%(filename)s:%(lineno)d} %(levelname)s - %(message)s',
-    # https://stackoverflow.com/questions/57925917/python-logging-left-align-with-brackets
-    format='%(asctime)s  %(filename)-15s:%(lineno)-4d %(levelname)-12s %(message)s',
-    handlers=handlers
+# WARNING (June 17, 2024)
+#
+# Original logger configuration logic worked well for verification logic but broke when using TF `data.external` mechanism.
+# (broke due to how the `data.external` mechanism reads stdout/stderr ... which log events wrote to by defaul). This was resolved
+# by splitting the logger into two: one to handle verification via stdout/file, the other to handle TF external mechanism by
+# buffering all log events in memory until a proper payload is returned to TF (with the buffered logs emitted afterwards).
+# https://docs.python.org/3/library/logging.handlers.html
+#
+# Trial-and-error reworking logic finally got that working, but allowing logging.basicConfig to remain resulted in 
+# double-entry log events. Not sure why and don't care to spend more time right now investigating. 
+# 
+# Ultimately made things more granular and less DRY, but it works so .....
+
+
+formatter = logging.Formatter('%(asctime)s  %(filename)-15s:%(lineno)-4d %(levelname)-12s %(message)s')
+
+# Validation Logger
+logger = logging.getLogger('VALIDATION')
+logger.setLevel(logging.DEBUG)
+
+validation_file_handler = logging.FileHandler(filename='verify.log')
+validation_stdout_handler = logging.StreamHandler(stream=sys.stdout)
+validation_file_handler.setFormatter(formatter)
+validation_stdout_handler.setFormatter(formatter)
+logger.addHandler(validation_file_handler)
+logger.addHandler(validation_stdout_handler)
+
+
+# External Logger
+external_logger = logging.getLogger('EXTERNAL')
+external_logger.setLevel(logging.DEBUG)
+
+data_external_file_handler = logging.FileHandler(filename="data_external.log")
+data_external_memory_handler = logging.handlers.MemoryHandler(
+    capacity=1024*100,
+    flushLevel=logging.ERROR,
+    target=data_external_file_handler,
+    #target=logging.FileHandler(filename="data_external.log"),
+    #flushOnClose=False,
 )
+data_external_file_handler.setFormatter(formatter)
+external_logger.addHandler(data_external_memory_handler)
+
+
+
 
-logger = logging.getLogger('LOGGER_NAME')
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index d425bd48..6d5a264f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,3 +14,5 @@ tmp.log
 **/venv
 **/.terraform.lock.hcl
 **/__pycache__
+verify.log
+**/data_external.log
\ No newline at end of file
diff --git a/000_main.tf b/000_main.tf
index ad37321e..d54b2b43 100644
--- a/000_main.tf
+++ b/000_main.tf
@@ -49,15 +49,42 @@ resource "random_pet" "stackname" {
 
 data "aws_caller_identity" "current" {}
 
+data "aws_vpc" "preexisting" { 
+  id = local.vpc_id 
+}
+
+# https://stackoverflow.com/questions/67562197/terraform-loop-through-ids-list-and-generate-data-blocks-from-it-and-access-it
+data "aws_subnet" "existing" {
+  # Creates a map with the keys being the CIDRs --  e.g. `data.aws_subnet.public["10.0.0.0/20"].id
+  for_each = toset(local.subnets_all)
+  vpc_id     = local.vpc_id
+  cidr_block = each.key
+}
 
 # https://medium.com/@leslie.alldridge/terraform-external-data-source-using-custom-python-script-with-example-cea5e618d83e
 data "external" "generate_db_connection_string" {
   program = ["python3", "${path.module}/.githooks/data_external/generate_db_connection_string.py"]
+  query = {}
+}
+
+data "external" "generate_flags" {
+  program = ["python3", "${path.module}/.githooks/data_external/generate_flags.py"]
+  query = {}
+}
+
+data "external" "generate_dns_values" {
+  program = ["python3", "${path.module}/.githooks/data_external/generate_dns_values.py"]
   query = {
-    tower_container_version = var.tower_container_version
-    flag_use_container_db = var.flag_use_container_db
-    db_container_engine_version = var.db_container_engine_version
-    db_engine_version = var.db_engine_version
+    # jsonencoding necessary for empty objects
+    zone_private_new          = jsonencode(aws_route53_zone.private)
+    zone_private_existing     = jsonencode(data.aws_route53_zone.private)
+    zone_public_existing      = jsonencode(data.aws_route53_zone.public)
+
+    tower_host_instance       = jsonencode(aws_instance.ec2)
+    tower_host_eip            = jsonencode(aws_eip.towerhost)
+
+    # subnets = data.aws_subnet.existing          # Adding in these values wont be known til created.
+    # ec2 = jsonencode(aws_instance.ec2)                     # Adding in these values wont be known til created.
   }
 }
 
@@ -71,56 +98,27 @@ locals {
   # ---------------------------------------------------------------------------------------
   global_prefix = var.flag_use_custom_resource_naming_prefix == true ? var.custom_resource_naming_prefix : "tf-${var.app_name}-${random_pet.stackname.id}"
 
-
   # Networking
   # ---------------------------------------------------------------------------------------
   vpc_id = var.flag_create_new_vpc == true ? module.vpc[0].vpc_id : var.vpc_existing_id
-  vpc_private_route_table_ids = var.flag_create_new_vpc == true ? module.vpc[0].private_route_table_ids : data.aws_route_tables.preexisting.ids
-
-  # If creating VPC from scratch, map all subnet CIDRS to corresponding subnet ID
-  #  zipmap -- turn 2 lists into a dictionary. https://developer.hashicorp.com/terraform/language/functions/zipmap
-  #  merge  -- join  two dictionaries. https://developer.hashicorp.com/terraform/language/functions/merge
-  vpc_new_cidr_block_to_id_public  = var.flag_create_new_vpc == true ? zipmap(module.vpc[0].public_subnets_cidr_blocks, module.vpc[0].public_subnets) : {}
-  vpc_new_cidr_block_to_id_private = var.flag_create_new_vpc == true ? zipmap(module.vpc[0].private_subnets_cidr_blocks, module.vpc[0].private_subnets) : {}
-  vpc_new_cidr_block_to_id_unified = var.flag_create_new_vpc == true ? merge(local.vpc_new_cidr_block_to_id_public, local.vpc_new_cidr_block_to_id_private) : {}
-
-  # Regardless of whether we build a new VPC or use existing, assign the subnet CIDRs to a common variable for subsequent subnet ID lookup. 
-  #  concat -- join lists of strings. https://developer.hashicorp.com/terraform/language/functions/concat
-  subnets_ec2   = var.flag_create_new_vpc == true ? var.vpc_new_ec2_subnets : var.vpc_existing_ec2_subnets
-  subnets_batch = var.flag_create_new_vpc == true ? var.vpc_new_batch_subnets : var.vpc_existing_batch_subnets
-  subnets_db    = var.flag_create_new_vpc == true ? var.vpc_new_db_subnets : var.vpc_existing_db_subnets
-  subnets_redis = var.flag_create_new_vpc == true ? var.vpc_new_redis_subnets : var.vpc_existing_redis_subnets
-  subnets_alb   = var.flag_create_new_vpc == true ? var.vpc_new_alb_subnets : var.vpc_existing_alb_subnets
 
-  subnets_all = concat(local.subnets_ec2, local.subnets_batch, local.subnets_db, local.subnets_redis, local.subnets_alb)
+  vpc_private_route_table_ids = data.aws_route_tables.preexisting.ids
 
-  # If using existing VPC, get subnet IDs by querying datasources with subnet CIDR.
-  # If building new VPC, make dictionary from cidr_block and subnet id (two different list outputs from VPC module).
-  subnet_ids_ec2 = (var.flag_create_new_vpc == true ?
-    [for cidr in local.subnets_ec2 : lookup(local.vpc_new_cidr_block_to_id_unified, cidr)] :
-    [for cidr in local.subnets_ec2 : data.aws_subnet.existing[cidr].id]
-  )
-
-  subnet_ids_batch = (var.flag_create_new_vpc == true ?
-    [for cidr in local.subnets_batch : lookup(local.vpc_new_cidr_block_to_id_unified, cidr)] :
-    [for cidr in local.subnets_batch : data.aws_subnet.existing[cidr].id]
-  )
-
-  subnet_ids_db = (var.flag_create_new_vpc == true ?
-    [for cidr in local.subnets_db : lookup(local.vpc_new_cidr_block_to_id_unified, cidr)] :
-    [for cidr in local.subnets_db : data.aws_subnet.existing[cidr].id]
-  )
-
-  subnet_ids_redis = (var.flag_create_new_vpc == true ?
-    [for cidr in local.subnets_redis : lookup(local.vpc_new_cidr_block_to_id_unified, cidr)] :
-    [for cidr in local.subnets_redis : data.aws_subnet.existing[cidr].id]
-  )
-
-  subnet_ids_alb = (
-    var.flag_create_load_balancer == true && var.flag_create_new_vpc == true ?
-      [for cidr in var.vpc_new_alb_subnets : lookup(local.vpc_new_cidr_block_to_id_unified, cidr)] :
-      var.flag_create_load_balancer == true && var.flag_use_existing_vpc == true ?
-        [for cidr in var.vpc_existing_alb_subnets : data.aws_subnet.existing[cidr].id] : []
+  # Map CIDR blocks to subnet IDs (depending on tf resource, either/or needed). 
+  # Cant delegate this to Python due to need to make multiple data calls.
+  subnets_ec2   = var.flag_create_new_vpc == true ? var.vpc_new_ec2_subnets   : var.vpc_existing_ec2_subnets
+  subnets_batch = var.flag_create_new_vpc == true ? var.vpc_new_batch_subnets : var.vpc_existing_batch_subnets
+  subnets_db    = var.flag_create_new_vpc == true ? var.vpc_new_db_subnets    : var.vpc_existing_db_subnets
+  subnets_redis = var.flag_create_new_vpc == true ? var.vpc_new_redis_subnets : var.vpc_existing_redis_subnets
+  subnets_alb   = var.flag_create_new_vpc == true ? var.vpc_new_alb_subnets   : var.vpc_existing_alb_subnets
+  subnets_all   = concat(local.subnets_ec2, local.subnets_batch, local.subnets_db, local.subnets_redis, local.subnets_alb)
+
+  subnet_ids_ec2    = [for cidr in local.subnets_ec2 : data.aws_subnet.existing[cidr].id]
+  subnet_ids_batch  = [for cidr in local.subnets_batch : data.aws_subnet.existing[cidr].id]
+  subnet_ids_db     = [for cidr in local.subnets_db : data.aws_subnet.existing[cidr].id]
+  subnet_ids_redis  = [for cidr in local.subnets_redis : data.aws_subnet.existing[cidr].id]
+  subnet_ids_alb    = (var.flag_create_load_balancer == true ? 
+    [for cidr in local.subnets_alb : data.aws_subnet.existing[cidr].id] : []
   )
 
 
@@ -148,23 +146,12 @@ locals {
   # ---------------------------------------------------------------------------------------
   # All values here refer to Route53 in same AWS account as Tower instance.
   # If R53 record not generated, will create entry in EC2 hosts file.
-  dns_create_alb_record = var.flag_create_load_balancer == true && var.flag_create_hosts_file_entry == false ? true : false
-  dns_create_ec2_record = var.flag_create_load_balancer == false && var.flag_create_hosts_file_entry == false ? true : false
-
-  dns_zone_id = (
-    var.flag_create_route53_private_zone == true ? aws_route53_zone.private[0].id :
-    var.flag_use_existing_route53_public_zone == true ? data.aws_route53_zone.public[0].id :
-    var.flag_use_existing_route53_private_zone == true ? data.aws_route53_zone.private[0].id :
-    "No_Match_Found"
-  )
+  dns_create_alb_record = jsondecode(data.external.generate_flags.result.dns_create_alb_record)
+  dns_create_ec2_record = jsondecode(data.external.generate_flags.result.dns_create_ec2_record)
+
+  dns_zone_id           = data.external.generate_dns_values.result.dns_zone_id
+  dns_instance_ip       = data.external.generate_dns_values.result.dns_instance_ip
 
-  dns_instance_ip = (
-    var.flag_make_instance_private == true ? aws_instance.ec2.private_ip :
-    var.flag_make_instance_private_behind_public_alb == true ? aws_instance.ec2.private_ip :
-    var.flag_private_tower_without_eice == true ? aws_instance.ec2.private_ip :
-    var.flag_make_instance_public == true ? aws_eip.towerhost[0].public_ip :
-    "No_Match_Found"
-  )
 
   # If no HTTPS and no load-balancer, use `http` prefix and expose port in URL. Otherwise, use `https` prefix and no port.
   tower_server_url = (
@@ -212,7 +199,7 @@ locals {
 
   # tower_db_url = var.flag_create_external_db == true ? module.rds[0].db_instance_address : var.tower_db_url
   tower_db_root = ( var.flag_use_container_db == true? var.tower_db_url : module.rds[0].db_instance_address )
-  tower_db_url = "${local.tower_db_root}/${var.db_database_name}${data.external.generate_db_connection_string.result.value}"
+  tower_db_url = "${local.tower_db_root}/${var.db_database_name}${data.external.generate_db_connection_string.result.connection_string}"
 
 
   # Redis
diff --git a/001_vpc.tf b/001_vpc.tf
index a5ae23b9..c1c2806d 100644
--- a/001_vpc.tf
+++ b/001_vpc.tf
@@ -35,22 +35,6 @@ module "vpc" {
 }
 
 
-# https://stackoverflow.com/questions/67562197/terraform-loop-through-ids-list-and-generate-data-blocks-from-it-and-access-it
-data "aws_subnet" "existing" {
-  # Creates a map with the keys being the CIDRs --  e.g. `data.aws_subnet.public["10.0.0.0/20"].id
-  # Only make a data query if we are using an existing VPC
-  for_each = var.flag_use_existing_vpc == true ? toset(local.subnets_all) : []
-
-  vpc_id     = local.vpc_id
-  cidr_block = each.key
-}
-
-
-# Needed to add this to get existing CIDR range to limit ALB listeners
-data "aws_vpc" "preexisting" {
-  id = local.vpc_id
-}
-
 # Needed to grab route tables from pre-existing VPC to create VPC endpoints.
 data "aws_route_tables" "preexisting" {
   vpc_id = local.vpc_id
diff --git a/012_outputs.tf b/012_outputs.tf
index 568e1753..2ff3bed9 100644
--- a/012_outputs.tf
+++ b/012_outputs.tf
@@ -27,5 +27,5 @@ output "redis_endpoint" {
 # Example for how to get values dynamically generated by `data.external`
 output "database_connection_string" {
   description = "Dynamically generated db connectino string based on tfvars selections."
-  value = data.external.generate_db_connection_string.result.value
+  value = data.external.generate_db_connection_string.result.connection_string
 }
\ No newline at end of file
diff --git a/assets/src/tower_config/tower.env.tpl b/assets/src/tower_config/tower.env.tpl
index 874df340..80c4001f 100755
--- a/assets/src/tower_config/tower.env.tpl
+++ b/assets/src/tower_config/tower.env.tpl
@@ -2,6 +2,7 @@
 # Generic Tower configuration values
 # ------------------------------------------------
 TOWER_ENABLE_AWS_SSM=true
+TOWER_ENABLE_ARM64=true
 
 LICENSE_SERVER_URL=https://licenses.seqera.io