I dug up my old development backups from that time and I had it backwards, the advice was to read user agent strings and link directly to the version of the browser your pwa was designed for if you saw they weren’t running the “right” one and were worried about it breaking.

So I was mistaken but the reality was weirdly still bad.

I don’t know if that’s still commonplace. Right now it seems like a lot of pwas target chrome because it’s the most popular browser.