We’re spoiled this year because beta 3 has been pretty damn stable overall. Battery life is not great compared to 15.6 but that’s to be expected for a beta. Apple only has about a month to get the final version down so hopefully fine tuning things like battery life happens soon. I also think tomorrow is more likely compared to Thursday but who knows.
I also think it’s too early for Apple to release public on the same day as developer, but it usually trails only by 1-2 days at this point in the cycle. This means developer has to come out by tomorrow in order for public to come out by Friday, unless they wait until next week.