"Bill in Advance of Receipt" is enabled-How does that impact item receipt?

We note that with Bill in Advance of Receipt enabled, the bill posts directly to COGS and there is no "receive" button on the PO. First question: Is this expected NS behavior to treat the transaction like a drop-ship? My PO had an "inventory" location specified, as did the linked sales order. The SO fulfilment had no GL Impact. Again, this is how drop-ship PO's work, but this case wasn't a drop-ship or special order PO, items were not checked as drop-ship or special order, and there was no preferred vendor or vendor price on the item records.

Inventory records are not updated for last purchase price or FIFO costing. This isn't a problem if there isn't any stock on hand, but would be if there was and purchase price or quantities received were different.