The SandTemple Adventure was a vague idea of a use for a structure asdialed wanted to build. The idea was you could go in (with or without friends) and get trapped and have to find your way out without breaking any blocks, but less a maze and more like exploring an ancient temple. The whole getting trapped idea is what we were going to work out first since falling sand is difficult to reset. That sand trap that would suffocate you was a design for a room.
But, the last update added similar things, so it hasn’t really been a priority.
As for Tower Control 2v2, the area I had set aside for SkyRace should work fine (the square over the co-op course). The thing with SkyRace is it’s in the sky – it can go anywhere.