One of the powerful things about having ships with modular cargo systems is that you get the temptation to start seeing what else you can pack onto the cargo racks. After all, if it can carry cargo, surely it can carry other things in a ready-to-use format. Or, if you have even more containers together all at once, you can have entire facilities transported ready to go.
This sketch was an outflow of this concept. One idea that’s been floating around in the back of my mind (though sadly not sketched out yet), has been the idea of a Provider-class freighter taken up from commercial service (or built for naval service). As part of that service call-up, the container racks are filled with prefabbed systems, like machine shops, barracks, and small craft bays to support other ships. Cargo storage is still retained of course, primarily to to support onboard systems. Think “Atlantic Conveyor”.