Apple urges developers to not use DeviceCheck for anything beyond basic device verification, and if you’re a developer that’s also misusing it, then you should definitely cease that—there are probably more reliable ways to check whether it’s the same user trying to access an account from a device or not.
I don’t think I care about not being able to erase the device ID. It seems useful to have this, actually, for back-tracing if need be.
Snapchat probs shouldn’t use the DeviceCheck services improperly. But hey, that’s just like my opinion, man.
More, not very interesting, info on DeviceCheck services here: https://developer.apple.com/documentation/devicecheck
Alternatively, if they are happy with their pro-grums, familiar with the interface, and not getting gouged worse than the next cable subscriber — consider letting it rest.
From things like being able to punch in a channel number to having the cable company to call for issues, folks in that generation might really prefer paying.
I’m basing this on my years of experience with a now 60-something and now 80-something. YMMV