Here is a video of Jef Raskin's Leap UI: https://www.youtube.com/watch?v=o_TlE_U_X3c #Emacs with Org-mode and EXWM looks surprisingly similar. It doesn't seem like it would be hard to make #CanonCat -like keybindings either. Need to get a Cat manual and think about it. Japanese 108-key QWERTY keyboards have a short spacebar with modifiers nearby that can serve as thumb-operated Leap keys as in the Cat.
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko