Thanks for taking the time to type the above and I agree with much you said about the season being more disjointed and about Max's beautiful growth. Where we may disagree is the purpose of those other character changes or reverting actions.
[spoilers]
Although the series has always been about protection and acceptance, this season seemed to double down there, less in supporting individuals/representatives, but more in looking at Sam's criticism of others in her life. She's a little challenged now. After giving Sunny and Rich feedback in multiple speeches and likely TV's longest laugh, she accepts and supports Sunny's choice (which after all is hers and isn't that unrealistic). Phyll is going to always be Phyll and you can continue to fight it or accept (and realize the parts in you). What lead to Max's secret from her mother and does she trust and believe her choice for support - which obviously she has a lot to do with ("And she was with you? She's okay?")? Etc.
And a whole lot of stuff about aging out and letting go.
So, while not denying some issues with the last season, I thought after four seasons of us riding and laughing with Sam's cynical judgement of the world, the final season looked at those judgements (which she probably needs to adjust a little, with love, understanding, and acceptance in focus through the discomfort). Everyone close to her made choices she disagreed with (some with reverting). And she came to peace-ish with them. The ending's end may be all delusion (hey LA aurora!), which itself may be a criticism of what immediately proceeded it, but it leans in the right direction, and I buy it.