Mostly, I like a little transparency on inactive windows as set through Settings Manager > Window Manager Tweaks > Compositor > Opacity of inactive windows.
However, when running programs with multiple windows, like Ardour or Scribus, this setting makes the main window transparent when one of the “sub-window” dialogs are active. This I don’t like.
Of course the easy solution is just to switch off the compositor transparency, but I’m hoping there’s a way to make one program behave as if it was one window? So in Scribus, when selecting the Properties window, the main window would still be opaque.