Wow I have been plagued with string snags lately. Especially with my Quicksilver hybrids. Even when throwing gently. After trying other strings and trying to figure out why I can only get half of my boomerangs to work with these tops, then I tried to figure out what changed in my throw. Ha! I found it. I have been playing after church a lot. Little kids will gather around to have a top in their hand. Of course they crowd in close. So I have been changing my arm motion to avoid whacking them in the head with my hand. This messes up my release. After realizing this, I straightened my elbow and when back to a more full arm swing. No snags since!!
Lesson to learn. Throw the way you teach others to throw :-)