If I was in your position of wanting to make an award booking, I would recommend booking on BA now and then keeping an eye out for other flights later; better to have a flight that meets requirements but isn't the best choice than to wait and gamble that the preferred choice will appear; the change fee for an award is not too bad

A lot of people fly on their birthdays and why would you expect the crew to "remember"?

It would only be a guess on when you may be able to make a booking