...You're already not equipping your carrier with jump drives, so clearly you know that you don't have to equip jump drives to all of your ships...
Yes, I understand that hangers are not necessarily required to jump ships, but one of my design goals is to reduce my jump-drive equipped ships to as few ships as possible. My original design concept for the original Columbus III was a single 50k ton jump carrier which used the largest military jump drive I possess. However, I was unable mount enough hangers on that design to make it useful. So instead I created the Lexington to work as a dedicated carrier escort for the Columbus III, with the idea that I would escort each Columbus with as many Lexingtons as the Columbus' jump drive could support. At my current tech, this results in jump squadrons of 3 Lexingtons for every 1 Columbus.
The only major reason the Columbus designs have hangers at all is to ferry the maintenance and fuel tanker ships. I don't like putting these ships on my combat carriers as they don't have a direct combat role.
Another major advantage that carriers seem to offer is that any ships docked in their hanger bays do not count up their maintenance clocks. They might even reduce them, I can't remember off the top of my head. I think docking also resets crew deployment clocks. So this makes logistics dramatically easier as carriers tend to serve as consolidated maintenance and fuel depots. For a larger fleet, keeping docked ship's maintenance clocks zeroed out will be very useful.
At some point I also want to explore using a commercial jump carrier as you described, however my understanding of the commercial hanger deck is that doesn't work quite the same as the military version. Something about the commercial hanger not reducing the maintenance clock or crew deployment time or something. Still seems useful but not perhaps quite as useful as the military version.
