I know this has been stated many times, but I want to make sure that I have this straight, because I might have a similar circumstance in the near future.
If I cancel a reservation that is using borrowed points, the way that I get those borrowed points re-assigned to a previously existing reservation is to modify that existing reservation after cancelling the other one (without making any changes to the dates, room type, etc.) and then the system will bring in those now-available borrowed points to replace current UY points, correct?