@BrodieOnLinux buttons/elements in CSD/headerbars won't break the dragging of the windows. That's not and never was an issue.
For apps who are stuck, the compositor usually gets this and asks the user to kill that app.
Apps who are frozen are however not movable by the mouse only. This is a problem.
DWD is a silly/broken idea. You'll need to have a fallback if your compositor/WM doesn't support it, otherwise you might have core functionality not available at which point i don't see why someone should do the work and testing twice. If it needs 2 implementations, it's broken by design.
@fabiscafe This is dependent on the GUI framework, and how it handles events. You can't inherently assume things will work properly
Usually is the key take away, and only if the compositor is smart enough to do so
This is a problem
It's only a silly broken idea if it has an inconsistent implementation across different desktops. Or you plan for your app to be used in other environments without thinking that far ahead