Attempting to Add "Limited Time Heads" causes CTD in tool

[Webmetz]

As I was attempting to add heads that were from limited time events, the save editor crashes. When I added them manually by adding a valid item, and adjusting the item balance and inventory data to match these items, loading the editor gives an "Out of Index" error.

FL4Kenstein's Monster via expired code | CustomHead_Beastmaster_25 Camoufl4ge Epic; unlocked through Vault Insider Program (VIP) | CustomHead_Beastmaster_26 4NU Bust (Borderlands 3 content creator head) | CustomHead_Beastmaster_27

These were the only ones that I had issue adding for FL4K.