When you borrow points I'm told by MS that is a somewhat final decision in that they must be used by the end of the UY you are borrowing into. If your plans change,can those borrowed points be rented to avoid losing them altogether?
Yes, borrowed points may be used for any of the usual reservations thru DVC (including rental) and are subject to all of the usual reservation windows and restrictions depending on the specifics of how the reservation was cancelled.
If the cancelled reservation was at a DVC resort and was cancelled 31 or more days in advance- there will be no restrictions. The only things you cannot do with borrowed points is transfer them or bank them.