There is nice feature in kde applications menu when you can right click at a menu item and set keyboard shortcut to it inplace. See screenshot. But in Window menu (that you see when press Alt+F3) there is no such possibility. See screenshot. When you right click it (for example, on a resize function, then you actually start resizing a window). It would be good to implement inplace setting shortcuts as well for Window menu. See screenshot. Operating System: Arch Linux KDE Plasma Version: 5.14.4 Qt Version: 5.11.2 KDE Frameworks Version: 5.52.0
Created attachment 116843 [details] How it works for application menu
Created attachment 116844 [details] How it is missing in Window menu
Created attachment 116845 [details] How it should be in Window menu
If I understand it correctly, these shortcuts must be global shortcuts. KWin doesn't use KXMLGui for its menus right now, maybe because KXMLGui does not allow to configure global shortcuts in the first place.
KWin doesn't use kxmlgui as it is a framework unsuited for KWin's need. Supporting another level of context menu is in KWin's case rather complicated and not really justified the effort. I'm sorry, but this won't be implemented.