I bought a second gen SE on craigslist while waiting for a screen for my Xs Max. I’m using it right now as a secondary device and don’t notice any particularly common lags on the SE2.

Battery health is down to 89%, meaning it was a little annoying to use as a daily while traveling but that was my only complaint (and I’d have no problem replacing the battery to alleviate that if I wanted to keep using it as primary).