Super cool! I think that it took me a bit to understand the difference between click + drag and shift + drag, which confused me for a while. Not sure if that’s just something that just needs to be learned by playing around with it, or if the documentation could be written to be clearer?
I also noticed that in some cases, shift-clicking on the left side of an image (to try to resize it) continually makes the image increase in size to the right, which definitely hampered getting the alignment right. It might have had to do with the fact that my image was really scaled down (it was an image downloaded from dndbeyond, which was like 5000px x 7000px, so I had to scale it down a bunch to try to fit the grid).
And sometimes, if I grab onto the image with shift-click right near the top, I will move the image around for a bit, but then suddenly my cursor will get close enough to the top that I’ll start resizing the image instead.