Super Freighter
This is a Miranda based transport capable of hauling four containers, although I haven’t printed that version yet. This is ship makes a lot of sense to me. If a Ptolemy with its reduced sized warp core can haul two containers at acceptable speeds, then a full size cruiser warp core should be able to handle more. I added a second set of nacelles to reduce the energy load per nacelles. With a full four containers this ship is 1.4 million cubic meters, about twice the size of the Excelsior class.
The holes in the containers is because I hollowed then out to reduce cost. The containers are also separate pieces that have been glued onto the main hull.