Your answer only partly answer my issue!
I have 2 tablets, both have 8 inch screens diagonally, none is rooted.
Older tablet running Android 4.2.2 has 16:10 aspect and it behaves like a phone, single pane if Deliveries opened vertically, double pane if opened horizontally.
Newer tablet running Android 6.0.1 has 4:3 aspect and behaves like "large" tablet, always double-pane regardless of opening orientation.
This is doesn't comply with your answer!
Both tablets are LARGE according to your categorization.
But one behaves like a small one and the other like the large one.
Because of this I can't view the tracker map-movements full screen on the newer tablet.
This is very annoying because the screen-size and screen-aspect shouldn't control this behavior. Even initial screen orientation shouldn't.
This should be controlled by app's Settings.
Please, make this optional in Settings in future version, soon!