Remove it, rebalance the largest transports at the 10K range, one for each house. Refocus trading en masse back onto tradelanes.
The more you remove the highest cargo vehicles from the lanes, the less interaction. Jumping barges is a no interaction machine unless the pirates find them or they're at the coordinates.
IMO, the RP aspect is "The house traders realized that the barge was a competitor. What the largest transports around Sirius could offer was a fraction of what the mighty boat could do. With jump drive technology invested in moving the massive barge to any point in Sirius, profit was being killed. This gave way to the next innovation in transport ship design. Newer, higher cargo transport ships were put into production. Though much smaller than the barge itself, they suffered for the increased capacity in becoming nearly immobile. However, they were still able to utilize the trade lane network, while doubling the quantity of cargo being sent."
Or something. I'd like to see a focus on the largest cargo ships being able to fly down lanes and get pirated.
Or I could get behind the long idea above (Gorvas) In that the barge becomes a detriment to the point that the profit isn't exactly existent. More of a mobile load off point. Fill it with resources, jump it, unload it. Its a bank, if you will.