When duplicating a part in PreForm, I noticed that it is possible to make an excessive number of duplicates of a part (e.g. more than will fit on the build tray). When I accidentally did this, I noticed that some of duplicates were created directly on top of existing copies of the part.
If I didn’t notice where the overlapping duplicate was during its creation, it would not have been obvious that there were two duplicate parts in the same position.
I think it would be a nice to incorporate software feature that either prevents the creation of overlapping duplicates or shows where you may have overlapping parts (e.g. highlighting them in red).