Oh hey, we built our floating bases in pretty much the same spot haha :) Mine's basically a big upside down pyramid, within and on top of which I'm building all my stuff. I can build higher up, but stopped at the point where the Shroud disappears off the map lol. Since Melodies of the Mire, I recommend placing small towers on each corner of the base with trampolines on top, makes great launching points for gliding :)
I did the same, but went much higher than you did moving the shrine about 6-7 times and building the jump pad up to the top of it's 160m ceiling (the altar stays in the center of the 160m square). At that height you are above the clouds and the shroud disappears. The fortress on the larger PoC mountain looks tiny. I will be crying if they patch that out. I named mine Starbase and have flown to all the towers - even the newest one.
I like "no physics" while I'm building but after I become obsessed with justifying my builds. Justifying this one would take years but I bet it would be fun.
Is there a limit to the height of ur altar position? I dont understand, can you move ur altar endlessly higher while building? I didnt play this game yet. But definitly a cool idea. Reminds me of gods platform from dragonball.