I prefer open shoes (slippers) in house, as I don't want to feel pressure.
My improvements ended after about 4 years too, but my "mental game" in dealing with it still keeps improving if that makes sense.
OTOH I went to a music festival a few months back, and apparently did 25.000 steps in one day/evening/night). No problem the next day.
The PN... It's there, I got it. "Deal with it dude" is what I tell myself (well, a condensed version of it). The less you fight it and concentrate doing doing fun stuff, the better you feel. So in that sense I am still improving.