Wow, that is interesting about the APN. I recently switched from Android to an iPhone XR, mainly because it was free from a relative, but also because WiFi calling and texting worked so flawlessly, and still does after transitioning to Boost as far as I can tell. It reminds me of how seamless it was on Republic before Dish (but without the WiFi/Cell handover, I suppose).
I think I’ve only ever gone so far as to manually enter APN values (and perhaps some others) into a rando-brand Android phone (Doogee), which I got from a friend when Republic switched to Dish (long story).
Anyway, is the APN the same for all iPhones typically? Also, once acquired through the app, is it something that can be AirDropped from one iPhone to another or transferred to a PC, then to another iPhone over USB? Or does iOS have it locked up tight? Most people would probably find my reasons for asking odd, but if you so choose to indulge me, I’d greatly appreciate it.