hard to say only. if you forget to turn gas off and it fill carb and airbox you'll need to drain them both. vent hoses get full of water and it travels into carb, again you'll need to drain them.
ive only had to pull screw twice, once for rolling it and once for not shutting off gas when trailoring. there could be circumstances other than these. if your worried about it then pull it everytime you when your not riding. i just wouldn't remember to stick it back in.