I read this as independent placement. That is independent placement for Draft Clone alike assembly solid feature. Or alternative description i guess could be "Part Tip" linked simple copy alike assembly solid feature.*overrides placement of child object, not adds another placement on top of it
And here i feel we will need to get clever as:
This assumes topology isn't an issue. It is and assembly constraints will break and will break often. Therefore FreeCAD assembly infrastructure should accommodate to that. I feel that if doable something like this could work:allows to make more stable links (as I proposed, links are to remember only instance path, so rearranging containers inside Part won't break assembly constraint links)
Each feature that can represent "Part Tip" gets UUID assigned. This would be useful in a lot of places not just for Assembly purposes. For example simple tool like adding a note to existing feature can't be made reliably ATM. As original feature label/name can easily change and the note gets assigned to another feature after. If there would be UUID that problem wouldn't exist or it would be greatly reduced.
Now Part Tip is a feature itself and lets imagine it has its UUID. Storing this UUID therefore is the only thing needed for assembly feature to preserve link to the correct feature. The Part Tip feature itself provides topology to assembly feature. Adding for example plane/face constraint to such feature results in creation/storage/using of signature pair like (one pair):
- UUID: value
- Face: 7
Likely one feature would need to be considered "base assembly feature" and after each constraint is resolved in some order independently. If something like this would be done maybe similar approach could be explored for PartDesign in the future. To better manage topology issues between features in the PartDesign workflow.