I dunno. I changed nothing else at all, updated PIF, rebooted phone, opened Messages, and like, it was immediately in rcs mode. It even received a couple old messages that has apparently been waiting on it to finally connect. Certainly possible that it was something else, maybe updating PIF happened to flush a cache somewhere, I dunno. If it wasn’t PIF directly, it was either a huge coincidence or some other indirect side effect of updating, cuz that was the only thing I touched, and it magically fixed the problem for me. ¯_(ツ)_/¯