First of all, thanks for this amazing expansion of the limits of VR, in more than one sense. I have been trying it for a couple of hours now.
1. Yes, eagerly waiting for a wall editing option
2. Unable to undo the first corner, after that I can undo but not the first one
3. Sometimes when making cubes, the third point makes the cube flow in the opposite direction than I'm moving my control
That's it for the moment, eagerly waiting your updates!