I am not an expert but I suspect this isn’t realistically doable.
- Google sells you a serialized pixel 5a with a google controlled root of trust.
- You log into the phone with your account.
- Google adds a database entry to your account with the serial/root of trust info.
I don’t really see a way to beat this except maybe buying a “still in box” unopened pixel 5a that has never been registered to anyone before and setting it up.
This assumes the program is still open. Google may have time boxed it such that you must have registered before the announcement or whatever.
All this being said be careful. Don’t get you account banned. You can’t appeal if google thinks you are doing something shady they don’t like.
Lastly I have to say this. I may be worth escaping the google ecosystem. Why let a company control so much of your life? Not related to this community, but an important point.