I’ve ascertained that this also occurs to GTK3 windows, presumably because their window decorations are also client-side, and that includes the border?
Additionally, KWin poorly disables them on quick-tiled windows where they border the display, but this is fairly minor:
@johnandmegh , actually, in this case, Spectacle is capturing exactly what’s rendered. When I tile a window to an edge, I see the window border wrap around the title bar, then stop at the window content, as depicted in the screenshots. I expect that this is a bug in the Breeze KWin SSDs.
