If you’re flexible, you can work concierge but I would never depend on such a booking for a specific date.
We were able to book concierge twice for the upcoming year, across use years.
1. We booked two days of three avail with our AKV points for a 1BR just ahead of the 7 month window for May, stranding one day that we were able to pick up at the 7 month window with other points. Later, after checking several times a day, another day became avail so we have a 6 night trip scheduled early in the year with 4 of those being 1BR concierge.
2. In Sept, just after the 11 month window, we found 3 nights in a studio abandoned by walkers and picked those up, waitlisting two more days which were subsequently also abandoned by walkers. So 5 nights in a concierge studio but none of those nights avail 8am at 11 mos.
And we had no control over the dates either trip was avail. We were flexible. Because we like concierge, we work our points towards them.
If you’re flexible and stalk you can sometime be successful. We’ve owned AKV for 5 years now and these will be our 3rd and 4th concierge stays.