AFAICT from looking at the imgui wiki page and the examples in the OP of the wayland-protocols MR, it seems to be entirely that either these libraries have exis

AFAICT from looking at the imgui wiki page and the examples in the OP of the wayland-protocols MR, it seems to be entirely that either these libraries have existing API that allowed setting the window coordinates and thus they want to be able to continue providing them, or these applications (like gimp) want to be able to recreate those windows at their previous positions after the application is closed and restarted. It's also worth noting that that imgui wiki link says the feature doesn't work well in X11 either, though I didn't read the linked issue for what exactly is broken there.