I absolutely love Emacs, but I can't understand why people want it to be their window manager, of all things. Emacs can be many things, but high performance it is not. And WMs definitely are a high performance area.
They’re really not. Stability matters, but a wm has very little to do with actual rendering, it’s more placement, title bar and decorations, emacs as slow as it can be would be perfectly fine unless you have some crazy extensions on top, hence running two instances.
