Three more solutions.
This version of Lixes in Motion is yet again different from Part 1 and Part 2, so is it supposed to become Part 3?
The new version of migration is really nice, you got 5 floater and 5 climbers, and yet things don't work out as easily due to the time limit. You might want to tighten it by 30 seconds or so, as I think building bridge and mining after each other might still be possible within 4 minutes.
Survival of the Craftiest presents a nice puzzle, though I suspect there's more solutions than just mine.
A Fearful Symmetry: In the new version, it's possible to cross the gap with 2 builders, so shouldn't the number of builders be adjusted accordingly? Might also be better to steepen the terrain that leads into the water to it's clearer that you can actually pass it with 2 bridges.
Eye of the Needle: that should work, do you mind if I replace the 3 16x32 blocks with a 32x32 one? Should still work and looks nice IMO.
Next I'll probably have a go at minimac's levels.