If i'm going to implement a custom vertical bar – how do i arrange for that? Any good doc / instruction?

We're supposed to keep away from the centre of the screen when Duo is half-folded (some sort of book / laptop-like pose). How do I do it in a right/intended by UIKit engineers way? Sub-Questions below: a) What's the proper way in UIKit, if I only have a frame of region? b) How to understand if division region is vertical or horizontal, and where shall i move my controls out of center? c) Do we get any layout guides for that?

Which parameters are exactly used to decide which controls are moving to the vertical bar? What are they (which priorities, other properties are used for that decision?)

Hinge interaction, layoutSubviews, etc – when we're supposed to get notified, and react to the change of pose/layout?