There are some category of villas that are not available on cash - such as the standard view at BW or the BCV dedicated two bedroom villa with two queens in the second bedroom. If you book one of these on points, and then try to book using cash, you might not be able to do it and would have to move. Also if you book through CRO and not MS for the cash nights, you may have to move. You will have to check out and check in again.