Good points. For making the polylines, one further issue is that some plot boundaries will need to be split not just at their corners, but also at points on their straight sides when there is a t-junction with multiple plots adjacent, otherwise triangular voids of no man’s land could appear in between. I think maybe the script Giulio posted here could be part of how to do this.
Also agree that further constraints might be necessary to constrain the plots to reasonable shapes, such as no very sharp angles. If the initial division is not fairly close to the final one, it could also become necessary to allow for some sorts of topological changes, which would make this all much more complicated.