Hi Mario -
As far as I know, this is not currently possible with our existing client libraries. While the pop-up is short-lived and automatically closes without user interaction, it is actually redirecting between Firebase and the OAuth provider, and back, to restore the OAuth session and authenticate the user. In that sense, this "reauthorization" needs to take place given the current client implementation.
In the future we're hoping to add automatic OAuth session restoration, such that clients can silently re-authenticate without having to launch user-facing UI. However, this is a significant undertaking on our end and requires server support, so that feature is a ways out.
The current workaround would be to manage the OAuth sessions yourself, either with your own server process or the OAuth provider directly in such a way that the OAuth flows is managed and automatically refreshed periodically, and simply authenticate to Firebase using the OAuth token - using the `authWithOAuthToken(<provider>, <token>)` method that you called out.
Thanks -
Rob