Every bow stave is different and every bow will react a little differently to initial poundage loss after shooting, lots of factors, the skill of the bowyer, the type of wood, the bow design, the relative humidity and host of others.
I know my bows well and tweak the tiller endlessly if they need it while I own them. I only shoot one bow, I have a bunch but find I am the best shot if I shoot one bow exclusively so I know its personality. I hunt and shoot tournaments with the same bow, I know when it is good to go after a brief warm up, it doesn't take 60 shots for me to figure this out.