I'm confused.
Surely, when receiving inventory, you would want to be choosing a different control account (which is for the debits to inventory on a receipt), rather than the category which controls the COGs account to credit for the sale?
POA does not allow you to change the control account on an line receipt (and it's unclear to me why you'd even be interested in changing the Category of the line detail).
From the Help text:
Category (required): The item category defaults from the IC Item or Sundry Item table category. Although you can change the category code, it will not affect any account posting because the item category determines the sales accounts for the item.