Okay since I kept seeing rocks move from after a rock breaks I tried to tractor in a rock but it was not possible. Then I thought why the hell are we not allowed to pull in a rock closer. When we see them drifting away.
I suggest a basic Infero style module that comes from data sites. It has a range of 30km. Limited to tech 2 mining barges, porpoise and Orca. Limit one per ship. It would lower ship speed to 0 similar to a cyno until its finished its cycle. So it would pin the ship until the 2 min cycle is complete. Tractor speed would be slow around 20m/s but affected by tractor beam bonuses.
This would allow groups willing to somewhat risk ships to move rocks closer together to have a person herd rocks but be vulnerable for 2 min at a time and obviously it would make the group easier to predict as well as it herds mining ships together as well.
With it being so slow it would take ages to move an entire belt closer to a structure for tether range the usual 120km. But it would allow for a group to pull rocks into a ball inside a belt or even asteroid belt with the risks of being pinned.