I am developing a Kwin script (https://github.com/tcorreabr/Parachute) using ClientModelByScreenAndDesktop registered in kwin/scripting/scripting.cpp using the KWin.ClientModel.OtherActivitiesExclusion option, but it doesn't seem to have any effect. The model always returns all windows regardless of current activity. Even though I have windows in just a few activities.
I'm also using other exclusions like KWin.ClientModel.NotAcceptingFocusExclusion and KWin.ClientModel.DockWindowsExclusion, and these seems to work correctly.