You are misleading in fact, you use terms such as:
“it won’t work on GrapheneOS”
“locking down everyone using android to ONLY Google-dependent method”
which make it sound like it’s a permanent and definitive limitation.
It is not, they can add support later, as they stated already.
> It's untrue to claim that supporting AOSP attestation only serves GrapheneOS and leaves out everyone using Google-surveiled handset.
hmmm, what do you have in mind? Publish it to F-Droid but not to the google app store?