This system has several problems.
1st: You can bypass it idk yet how exacly it works but if your character says "Queue max list" without even selecting one, you restart the client and re-enter and you wont have any limit, you can target infinite stones.
2nd: Sometimes non-premium players can queue metins, randomly they can't.
If you found a solution and can share, i would appreciate, i don't have much of a time to fix this.