Registered tiered multiblock machines could use a parameter for enabling batch crafting and require a batch size and eu cost multiplier parameter for each tier.
Otherwise, to make regular recipes and regular batch crafting multis tier-able, the tiered multiblocks could also use an already defined recipe type, like registered batch crafting multiblock machines already do. This would allow for multiblock machines like a Large Chemical Reactor to be upgradable based on the coil used on the multiblock top, for example.