There's much more to the validation protocol than just HWID/serial. See https://github.com/JJTech0130/pypush/blob/main/emulated/data... for a list of the data that is pulled from the platform and used for validation. I would assume that Beeper registrations either use data from a pool of real devices, or made-up data that Apple might "permit" (because hackintoshes) but can definitely detect and block at any time.