Here's part of the explanation - I'm still not wrapping my arms around exactly what has changed - I'll need to walk through an example because the explanation seems to be leaving out a few steps or key needs:
We can no long use the Purchase Unit of Measure on a sales order. This is a frequent need for us as we have many items in ""each"", ""pack"" or ""box"", and ""case"", and have customers that order in all three. They prefer to have their confirmations, packing sheets, and invoices match their order quantity/packaging.
We would switch the UM on a sales order to confirm packaging quantities and now have to go to inventory inquiry to confirm case quantities.