Has there been any talk about supporting this kind of fullscreen?
The way it works is that the window is created without a titlebar/borders/anything (WS_POPUP) on windows I believe. The window (100% client area) is scaled to the current dimensions of the user's desktop. It hides the menu bar.
It has no mode-switching and is easy to switch between windows. It is very much preferable to me and I wish more games used it.
In Pyglet, it is the only option for fullscreen.