Hi @steven.oeyen ,
Welcome to the Auth0 Community!
I did some research around this topic, and looks like the only solution is what you have described.
Adding access_type=offline&approval_prompt=force to the authentication request, then Auth0 forwards those parameters to Google, and Google returns an access_token and an refresh_token.
I understand that you don’t want users to see a redundant consent screen being displayed every time they log in. You are welcome to submit your feedback here. Hopefully it can attract more votes and be implemented soon.