Sorry, don't know what the official answer is, but I have used an AC given to us for depositing Marriott Waiohai, for another Marriott. (Desert Springs) I usually just go to II online, and pull up everything available. To check to see which I am not getting for the AC, I also put in one of my regular Marriott weeks to check, and it does show some Marriotts which come up for the regular week, but not for the AC.
However, I am just guessing that if there is enough availability, one could use it, just as if there is enough availabililty in the 60 days prior to check in, you can often exchange a studio for a two bedroom first rate Marriott that you could never get in a regular request. Just guessing... am sure someone knows the answer. Ours did say we could not use it for the home resort, but other Marriotts did come up. Of course you don't see Waiohai online very often anyway.
Good luck. Just keep trying it online and see what shows up.