Just an idea if you add this dimension, you could make it into a closed off city with quests and puzzles.
I believe this might make it less boring, force you to trade with them (you wouldn't be able to break blocks), as well fit in with the mod. You could use prebuilt or generated dungeons to unlock new schools of knowledge in your lexicon. This would also challenge you to use the higher-tier weapons and gadgets like using the mana-blaster with phantom lense to open a door or activate a trap in the boss room. So to unlock the next dungeon you would have to solve a puzzle or code with botania's own tools.

I believe this would be a fun addition to the mod while not altering the basics all that much