You are absolutely right.
And as you seem to know how to do the programming, maybe my observation here helps to sort the bug:
Sorry bricbric but my AOG on stationary computer stalled because I have no steer-board connected and only running ver. 5.4! (had to delete user.config to continue, after loading test tractor.xml)
In figure 6 the u-turn go 90 degree right and “must” stay between yellow and green lines therefore does a circle to hit the correct track on line.
But in 7 the U-turn follow the boarder and can still turn down correct track on line.
I remember at some time “months ago” the program was improved, so following the boarder was possible, maybe this improvement is not implemented at all types of skips?
(Maybe if distance between yellow and green was bigger, or a different angle between boarder and AB line would change the behavior)
I know that my 8 shape in ver4 happened at 1 skip, coming to a boarder at an angle of around 45 degree.