from Make to Buy - you cannot use inactive bill types - Inventory Advisor

Hello fellow Sage users,

We have one FG item that used to be Make, but in the past years we switched to Buy. We thought about putting the BOM into inactive status, but when our sales team enters a line with aforementioned item, Sage generates the error "you cannot use phantom/engineering/inactive bill types". 

The reason why we care about putting the BOM into inactive, is because we use Inventory Advisor, and it has been suggested from their team to put the bill type into inactive so that it wont be imported in Inventory Advisor, hence it will not affect raw material computations when there is demand for the FG but only trigger a PO request.

Any ideas?