It's a bit of a mess, but have you tried using emacs-webkit[0]? You can have vi-style keybindings via evil-collection, the window management is pretty good, the

It's a bit of a mess, but have you tried using emacs-webkit[0]? You can have vi-style keybindings via evil-collection, the window management is pretty good, the browser engine is pretty standard. I've used it with spacemacs, and it's overall a decent experience. It's not quite Gecko though, and I don't think WebExtensions work yet. Also the single-threadedness of emacs itself can be a bother (of course the browser component is separate).