I see others have made this feature request before, so just adding my vote here. The ability to drag and drop to reorder PO items would solve a lot of specific types of re-ordering that I need. Some suppliers want things in SKU order, sometimes I want to group things into logical sets based on fundamentally arbitrary criteria, sometimes I need to modify a PO and need to insert an item into a specific spot in the list.
If either method of bulk-adding items preserved entry order, I could control the ordering at the time of entry, but right now it appears as if the items are being re-ordered by what I think might be creation date for the item. So the only method available to me of controlling the order of the items on the PO is to enter them singly...a task so tedious it encouraged me to pay for the PRO version. Bulk adding is awesome. Bulk adding with no practical control over how the items are being re-ordered is less than ideal for me.