What happened was that boots that were damaged, could be used to fly with, any the plugin wouldn't remove the boots.... so you could just use one pair of flyboots and repair them (dmg them slighty) and fly
I wouldn't mind that game mechanic so much if your boots took dmg over the time you are flying, however it also doesn't get votes for the server much. And thing is the plugin hasn't been updated in ages, and it worries me as there is no alternative plugin that does similar.