I'm pretty certain you can specify the amount you want to apply to rather than just putting the card down you could have them charge X amount to the card and if there was a remaining balance, have that go on a CC or return the last morning to do the additional amount.Checked out of Kaua'i Beach Club. The evening before check out I stopped at front desk and asked about applying the card.
Got the same response as at Westin Ka'anapoli - that if they applied the card ahead of check out time, I would not get a refund of the balance.
So waited until check out, applied card and have a balance of $29.