Room composition/module requirements
I think it would make more sense if any sub-type of a block would satisfy workshop/module requirements for rooms. Such as the kiln's room requirement being satisfied as long as 32 of any type of mortared stone blocks are used (like wall or floor blocks), rather than strictly 32 "mortared stone" blocks.
If room contains 32 of type mortard stone = room requirement met.
you can have multiple in one room, even if they require different blocks, aslong the block is present in the room, they work, granted the room looks alittle funky, but it works