I think it's best to do an award hold before you transfer your points. Just in case it's phantom availability.

Call SQ and tell them you have initiated a points transfer and are waiting on them. Once your points are in you can confirm the reservation.

If the agent says that's not possible just HUCA. This time phrase it in a way that you need to make an award reservation so they will initiate a booking. That usually comes with a "ticketing time limit" of two weeks which should be sufficient enough for the points transfer.