Wow! That's really impressive! Well done to everyone involved.
Does the community spawner still work so you can make more TNT for the next room? Is that why you started another project, or just fancied a change?
I use my own spawner, (still got 2 double chests of sulphur to use up) but most of it is dug by hand because of the patterns.
It moved location mostly because people had built all over/under where the main part would go so rather than destroy lots of work we moved, also get the new resources out here and the biome has some amazing scenery.
Also it means we can build it bigger and more fancy looking from what we learnt on the last version.
Atm to do list is;
Sort out decorations and lighting in the portal room.
Create some form of room/chamber on the nether side of the portal and collect a lot of light stone etc.
extend side stairs (also find way of making easy path from middle to side at the junction.
Create room above portal room with glass column in centre for the portal occulus (oh I've had a new idea on this btw ill post up a sketch in a bit).
(also apparently in the nether our location is -4500 on the z axis (on normal world we're -35,000) so if we can find the new town might look into making a tunnel or track to their station to connect us.Otherwise it's back top the massive powered canal on the surface.
Lot's to be done and most of it by hand.
But for the next big chamber a lot of tnt will be needed to speed things up and then we're going to need an insane amount of lapiz, gold, iron, obsidian, wool and dyes.
decorating that one will take quite a while but the plan i've got for it will let it be speeded up by having multiple people ,working on different things (assuming we can get volunteers

).