Is it possible to have multiple units of measure available when using Blanket Agreements?

Summary:

When creating a PO, we have a situation in which our Pricing on our Purchase agreement is in a Base Unit of Measure, or smallest unit of measure available for the item, but we purchase it in a different Unit of Measure which can be achieved by having a conversion factor. (Example: Lumber pricing in Board Feet (BF) but we purchase by Each (EA) or Pieces (PC)). We are being told by our implementation partner that when using Requisitions, and applying a Blanket Purchase Agreement (BPA), that the PO must be in the Unit of Measure in which