I bet the kinesis foot pedals would take emacs to the next level too. I use spacemacs in evil mode so I never bothered having to learn all those key chording things for emacs.
I have a kinesis advantage pro with foot pedal but the pedal just sucks to use. Foot is way too big and clumsy to keep pace with fingers, plus it forces you to sit in fixed position or fiddle with the pedal all the time to try and keep it in a comfortable position (trying to use the pedal shows how much I shift around in the chair during the day, nevermind when using a balance chair on wheels).
I rely heavily on the foot pedal. The single-pedal is too light and really wants to be bolted to something heavy so it doesn't slide around. The triple-food pedal is much nicer, just because it's heavy and stays put. I map all three foot-buttons to the same thing.
I used the triple-foot pedal for about 1.5 years. I now have chronic discomfort in my left foot; the one I used for the foot pedal. Of course it might be a coincidence, or it could be a RSI from using the foot pedal.
