After changing that setting, when I tried to create a topic with an all caps title (or rename an old one) it said: Title seems unclear, did you mean to enter it in ALL CAPS? It offered one answer - “OK” - and when I clicked on it, it went back to the editing screen and didn’t allow the creation/renaming to happen. The answer was to tick allow uppercase posts (allow all caps in a topic title or a post body) in settings. That setting seems to take priority over title prettify - which I have ticked again, as it has its own benefits. If I were to keep the old allow uppercase posts setting I would change the pop up text to something simple like “Titles or posts can’t be ALL CAPS: please edit”.