I've had several, and they're no different in construction from any other pvc line with braided nylon core. The line won't unravel or anything like that if it's cut (neither will real silk, for that matter). I assume you're talking about cutting some of the running line on a WF line? You can also cut a DT line in half, or cut from the middle and epoxy splice the two heads to get a DT of shorter length. I've done that many times to get 60 to 70 foot DT's that fit on my reels much better, and they've always performed and lasted as well as whole DT's. Bottom line is, anything you can do to a 444 (peach), you can do to the 444 Sylk (although it's not quite as tough a line).
-CC