Any reason why addon windows (like Global Search) have to be dialogs?

Just wondering if addon windows have to be dialogs, or could also be coded by addon authors as regular windows?

Reason I’m asking, I have the Global Search addon skinned as a full-screen window, like many others have done. Now I’m trying to add a global menu, so I want to add the menus to the Global Search window. Because Global Search is a dialog, I can’t open other windows from it, AFAIK.

Any way around this? Thanks!