Yes. People will warn you that it is risky because member services can make mistakes when filling the waitlist, but I have had very good luck doing this several times this past year. Create the waitlist online, then call up member services and have them add a specific note to the waitlist that says “replace dates x, y and z of poly reservation with Beach Club, keep remaining poly nights”. I did this successfully four times as I pieced together a Beach Club stay for food and wine, creating a single night waitlist and as each night came through they took one night off my original AKV reservation and added one night to my growing Beach Club reservation. One night waitlist date more likely to come through, that’s why I did it this way.