I dont think a bow should move at all in a year if its properly built and braced. I was thinking general use after 5,6 or even 7 years of shooting it. I didnt say your bows are tillered wrong, I wouldnt know if they where. A given bow, in general, shouldnt take on set that quickly if its tillered well, built well and braced correctley. The few bows I have made that "caved in" as I call it had design issues, and or tiller issues. Most have been fixed with reheating and retillering, as most of the worked wood is removed.