Imagine you are at a very packed mine, You see tons of players, You lag due to the fact that there is too many entities. If you happen to get a full inventory with all your mined items, you go the the sell sign at your ranks' mine, People are blocking it and you can't sell your items. We can solve these problems by adding a plugin that you can toggle players on/off. This would make things so much easier.
If people are blocking the sign, just tell a moderator and we'll kick them ^.^ But having this is probably easier. Support.
Support But also think how cool it would be if u could buy your own private mines and those also reset :3