I have observed an issue where if a player possesses two copies of a paricular item of clothing, and then picks up a third copy, the inventory will only show one copy of the item.
Essentially the last item is decrementing, instead of incrementing, the number of copies of that item in player inventory.

One of the places I have observed this issue is in Harland's inventory when I console killed him during Come Fly With Me. That is the source of the save file corruption in Come Fly With Me.

I suspect that the problems related to save corruption in Vault 3 are related to multiple copies of Vault 3 Jumpsuits in a similar fashion.

I dont have a save file that demonstrates this, so I can't hand this to you on a plate, but I'm a QA Program Manager IRL so I'm confident your team can handle it from here.

I'm 100 hours of gameplay in and loving it, despite the usual host of glitches that have accompanied this engine since Morrowind. Cheers.