Incorporate notes from #592

Author: edemaine

src/routes/reference/reactive-utilities/batch.mdx

@@ -64,6 +64,7 @@ in a few cases:
 
 * Within [`createEffect`](/reference/basic-reactivity/create-effect)
   and [`onMount`](/reference/lifecycle/on-mount)
+  (unless they are outside a [root](/reference/reactive-utilities/create-root))
 * Within the [setter of a store](/reference/store-utilities/create-store#setter)
   (which can update several properties at once)
 * Within array methods (e.g. `Array.prototype.splice`) of a
@@ -72,8 +73,8 @@ in a few cases:
 
 These save you from having to use `batch` yourself in many cases.
 For the most part, automatic batching should be transparent to you,
-because accessing a memo will cause it to recompute if it is out of date.
-For example:
+because accessing a memo will cause it to recompute if it is out of date
+(as of Solid 1.4).  For example:
 
 ```ts
 batch(() => {