Nope, I’d book at a rate you feel comfortable with, and then look out for discounts as the time goes on. You can always cancel and rebook, or call and have your rate adjusted when you see a lower rate.
Interestingly, I booked end of September this year, last year at a ST rate. When AP rates came out, there was nothing available when I booked. But I kept checking, and just today, saw a better AP rate for the first time ever since I booked. Called, and with then a less than 5 minute wait, got them to change it to that lower rate. Wasn’t a big amount, but a couple hundred dollars saved makes me happy.