My apologies, I have no idea of the difference between a ROM and a mobile OS, since I use both interchangeably (colloquially speaking). Is this a GNU/Linux like affair?

I didn’t know about play integrity. Is this new with Android 14? I’d be OK with not caring but most mobiles in the US don’t have custom ROM support any more. I’m waiting for KernelSU and custom patch support to grow so as to modify my mobile at all. I do not like where the industry is going. Even the FP5 was not released here (absolute shame)