So here is my solution to the problem.
Couple of notes - I only require the panels to be moved to the fabric - not rotated. It is important that the thread line directions are known/controlled in the process. This allowed me to cut the nesting code down to just a single jitter.
The nesting is done with just the outside curve (seam allowance) and then a separate piece of code works out what was moved where and does the same to the groups.
Actually easier than I expected and this will be a great feature for my tool.
Downside is the run time, about 40 secs for just these parts, and the complete program has a lot more - might not include it as a live feature in the main code base but use the data dam and a button to run as needed.
180601_nesting of groups_solved_discourse.gh (255.4 KB)