I used to use (and love) ShortCat, but it got too slow on my ancient MacBook Pro. I switched to Mouseless, and I actually prefer it now.

Yeah, I tried on an Intel MBP years ago when it was first launched. It was super slow, and I disregarded it. I just gave it a try on an M4 Pro; it's not instantaneous like Vimmium, but it is usable. I am sold!