You can get all kinds of mini android phones in China. Check aliexpress
[1] https://willmyphonework.net/ [2] https://www.frequencycheck.com/
I'm not claiming it's unknowable, I'm claiming it's often known to be terrible. Purism, PinePhone Pro, Fairphone, Sony Xperia, Nokia 8.3 One, and other desirable phones support maybe half of the bands I need!