Hello ! Such a fantastic tool, so useful and streamlined. Loving it :)
One thing that I do find a little bit annoying though is the way it deals with mouse position when painting, as I somehow find myself clicking/painting on the wrong tile quite often and I am not exactly sure why.
Maybe it is just the thick border preview that is throwing me off. It might be interesting to see how it feels with it turned off altogether, or maybe having the preselection border highlight be within the tiles as opposed to bleeding outside of them ?
This is very minor of course but I feel like there is something subtle to adjust there. Now that I think of it I suppose that Minesweeper would be a good reference to look at.
Also, unrelated : color and depth# selection seems to happen on click-release as opposed to on-click, which leads to alot of missed inputs when working fast.
I hope this helps ! And thanks again for this great tool.