You know this would backfire in an instant, people instead of wearing lower lvl gear according to their job/class would be wearing gear of any sort just to get into the dungeon. Aka instead of a healer wearing a ring with mnd/piety, etc they would probably just throw on a tanking based stat ring instead. Not only this but once you meet the requirements for an ilvl you can easily get in and then switch out gear and then you're back to square one. You would have to enforce a no switching gear rule, which then would affect getting gear and equipping it as you go along in said dungeon but also the wrong stat equipment would still be in affect which wouldn't help the party either way.