Excellent thank you both, I missed window level option.
Follow up question: can these options work in similar way to TabletPro, where you can have this left hand panel, and it occupies that part of the screen, similar to Dock and Menubar? Then if I have floating menu on left side, safari on right side, if I close safari, and open a new app and maximize it, it fills only that remaining space, leaving the left panel visible.