Would be great to add Stamps that don't rotate along with the camera.

It's nice to be able to have them rotate with the camera, but if you want to make properly orthogonally aligned stamps, any camera movement has a tendency to mess with that. The best way to do it is to have hand zones at angles you want, change to that color, and press space, which is quite a workaround...

The way this would be implemented would simply be with another Stamp tool, hidden under the first one, like how rotating snap points only show up if you mouse over the normal snap points. And if you use that tool for stamps, rotating the camera simply won't rotate the stamp.