I think a hosted browser might be key to solving this. Something like Mighty (https://mightyapp.com https://mightyapp.com) if it were self-hosted or somehow run

I think a hosted browser might be key to solving this. Something like Mighty (https://mightyapp.com https://mightyapp.com) if it were self-hosted or somehow run by an org you could trust (or be run in some verifiably zero-trust way).