Most definitely a Mining Barge III needs to be developed.
A mining barge that is able to deploy up to three Heavy II Drones with a reduced mining bay, one high slot, three mids and two lows with two rig slots would fit the role in between the barges and Porpoise.
It would be a heavy shield tank coming in at 35% resistances across the board with an overall EHP base of 15,000 points.