Manufacturing Accounting – Revalue Average Cost Inventory

Hi! We went live with NetSuite in July of 2022 and have been using two systems since (now March 2023).

I want to do away with our old system, but in order for me to completely go live with NetSuite,  I need to re-cost all  inventory to make it match the old system.  My ACS team is telling me that I have to zero out inventory and re-enter in the inventory as an inventory adjustment with the new cost.  The problem is I am trying to do this as of 12/31/22, and we do not allow inventory to go negative.

Any and all help or insight is greatly appreciated.