While I don’t think there is a 100% guaranteed way to get a good boarding group as some are in the app prior to 7am and play around and get one, myself and others never open app until 7am. (See my prior posts 2 pages back)
Now from what I’ve seen people post, those who are in early and refresh app and bounce between screens, when it works, they get a good boarding group. BUT you may not get anything by being early and that will cost you even more time.
Going right at 7am, seems safer and more consistent (based on my results) even if you are not getting a sub 10 group.
@disneygeek90 has with this method. I will consistently get between 10-30.
So live dangerously or go steady/guaranteed