I'd ask the bowyer for their opinion, but mine is it's fine to leave a laminated bow strung. I've been shooting the same one for around 15 years, and it's spent more time strung than unstrung. My bowfishing bow, which doesn't get shot much other than when I'm bowfishing (short season), stays strung most of the time also.
The only reason I would unstring them is if I had them stored where kids could get to them, if I was afraid of a mouse or pet chewing the string into, for travelling (if I have to), or if it's a selfbow.
FWIW, I just scaled my bow (the one I've been shooting for 15 years). It's marked 60@28, it scaled 59.5@28. There could easily be .5# difference in my scale and the bowyer's. It's been strung since I got back from NM in September.
Chad