There is another glitch through ceiling glitch you can do in the Unlimited Mining servers.
It doesn't work the lower you get in the map thanks to getting even closer to the ground.
I assume it would even work in a normal sense if you're really high or far from spawn thanks to crappy location/collision detection.
Just stand in a corner, and just jump and jet at the same time.
100% reliable near the gamemode spawn. You'll know when you can't do it when the models stop warping while you move.