I read a (kind of old) yoyo book, and it said that often unscrewing a yoyo can mess up the axle. I unscrew my yoyo all the time to get out knots, but don’t want to break my axle.
It’s only a problem if you are not careful and cross thread it putting it back together.
Yeah, unless it has an extremely short axle and you are carefull, you’ll be fine, unless you are throwing a YYR.