> that let Pixel users enable VoLTE anywhere

It did a great deal more than that. It also allowed the toggling of VoNR, which apparently affected the fallback behavior of some people's services. (Ie. It would fall back to LTE and not roam back to 5G data unless nudged manually)

However for me, it would enable backup calls over a secondary sim card's data, which would allow text and calls overseas without the usual extortionate charges. Oddly enough, I believe that toggle is enabled for my carrier... but only on iOS.