Hi! Thank you for addressing all the bugs and adding all the cool new features, the UI scaling especially helps my tired eyes a lot :). Much appreciated.
I was wondering if you could consider adding the following: axis lock for handles.
E.g. holding down a modifier key (shift or ctrl) would lock a handle you're dragging (edge or corner) to one of the major axes. This would make edge dragging even better, it'd be nice to, say, drag the left edge of the grid and only have it move horizontally to preserve the top and the bottom edges rotation.
Could also be diagonals instead of axes, especially for corner handles, but that's ultimately up to you.
Tangentially related, discrete steps for rotation (say, 5 or 15 degrees) when rotating the grid would also rock. That's a less important feature probably, considering how photos people use for textures rarely align to these perfect angles. Still, that's a definite nice-to-have thing for some time in the future.
Thank you for your consideration, regardless of whether any of this is something you plan on doing!