Right clicking the title bar in a libcosmic app exposes a lot of useful things: creating window stacks, taking screenshots, minimize/maximize, moving windows around workspaces, etc. However, there is currently no way to bring up this menu in, for example, a GTK app which uses client-side decorations!
Right now, holding Super, then holding right click allows for resizing a window. It would be great if holding super and tapping right click would open that context menu in any application. As a bonus, it also allows for opening it in COSMIC applications without having to first aim the pointer at the titlebar.