Looks great, once you can make it v5 compatible I will get it!! And just to be sure, take your time xD no rush, I think that its a really good idea, been wanting them for a bit now xP. Keep up the good work!
I've just semi-Reverted the code to a previous version, so the redstone will no longer work but the sponges will work, also it should be a little faster than before! Once the flatmaps are done i'll work on releasing Lava, Water, Redstone, Fire, Mega (Fire, Lava, Water, Redstone), Super(Mega with bigger radius).