No help here sorry but some idea to discuss.
Eyesgood What frustrates me is wholesale re-writes of critical systems and features that force developers to re-think pretty much everything about said features, when it wasn't even necessary. Why not take an incremental, backwards-compatible, community-led approach to improving the tilemap system, especially when it already worked?
I think pretty much the same regarding containers, devs have changed many things (margins getting allegedly offsets but I didn't found any).
I guess documentation need a lot, I mean really a lot, improvements, more official tutorials, more about migration, new features, changed features and mostly, the why. Devs knows, discuss between them on github so this generate thousands of interesting discussions which will never be sorted and organized anywhere else whereas all those knowledge could benefit the community.
I'm aware it would need quite a lot's of work too to do so but the best tool in the world worth only how users are able to use it the right way and if no one use it, it worth nothing. Unfortunately, this work cannot be done by anyone who want as it needs prior knowledge of the engine and dev process.
Youtube videos are great on their own but unfortunately, abundance make things worth than better, as among good ones there are tons of bad ones too I guess, people going in all directions, give their own "best ways to do this or that" and guidelines which may contradict one another. A central library officially "approved" in a way or another, would be welcome.