OAUTH2 support for GMail in Pegasus Mail is now very near - the code is complete and in active testing with the beta test team: we aim to submit the code to Google for approval in the next couple of days, and if they are as good as their word about how long that process will take, then we are aiming to release v4.81 with OAUTH and other fixes around the middle of May. Sorry to cut things this tight - it has been quite a process.