I cannot see how commercial hangar are going to be useful, say you want to transport 20 fighters 4 systems away and the transport take 2 months to get there, your fighters are aimed at 1 month deployments, and maintenance at a bare minimum. Because you extract speed out of it. The fighter engine or what is going to blow up even get to the destination, after runnign out of parts. Even if you do have a module since fighters have short engineering bays, it be drawing part every a day or 5 day cycle, you run out of parts on your 20 fighter very fast.
Unless Maintenance is stopped the commercial hangars are useless for transport. I would of love to see comm hangars the same as military hangar except you cannot launch fighters unless around colony orbit.
The commercial hangar bay is mainly for repairs. However, I have had fighters sat in orbit for months waiting for a carrier with no maintenance and not had any failures. Although they have no engineering spaces, their chance of failure is very low due to their small size. For example, here is the relevant portion of the US fighter from my current campaign:
F-40 Starfury class Fighter 300 tons 2 Crew 53.4 BP TCS 5.99 TH 42 EM 0
7011 km/s Armour 1-3 Shields 0-0 Sensors 1/1/0/0 Damage Control Rating 0 PPV 2.25
Maint Life 0 Years MSP 0 AFR 59% IFR 0.8% 1YR 3 5YR 43 Max Repair 13 MSP
Intended Deployment Time: 0.5 months Spare Berths 0
The class AFR is 59% per year and that is the rate when the fighter has already been in space for a full year (it starts at 0% and will get to 59% after one year of deployment and continue getting higher after that). A fighter with a low deployment clock will have very little chance of failure. A 3 month trip aboard an auxiliary carrier would be very low risk.