Yes, leaving it strung is fine, actually best if hung properly. Norm told me and I have done it quite a few times, to do it with the bow strung and leave strung. You want the tension of the string when doing it withour heating it. I actually was on the phone with him when I first tried it with a bow he had made and the original owner got the twist in it by leaving it standing in a corner unstrung. I was worried at first and he told me to give it a good twist, said if the limb broke or delaminated he would make me another pair for free, that is how confident he was. Shawn