If I am reading this right, you are talking about using a subby as a dedicated System Defense/Customs ship not an auxiliary to your system Navy but a primary ship. ...
Yup. Jump is there mainly to get it to the system that buys it, to go elsewhere for repair of battle damage to the ship or its brood if needed, or to go to pick up replacement fighters. Other than that, it's intended mainly to stay put in that system.
... Personally I would up the M-drive to 2G and get smaller fighters like the 8 d-ton fighters from Broadsword. This might give you more configuration options. :devil:
If the system Navy is buying one (or more) of these for system defense, then you could get by with removing the Jdrive from some of them and installing more powerful Mdrives and more fuel... assign one to police around each gas giant, and another around each inhabited planet.
They can function as Customs/Police vessels, but can be a nasty surprise for light-weight opposition.
Keep a few others with Jdrives, for re-enforcement of the "station" ships as needed.
All good options where there's a budget for it. Some systems won't have the equipment for major modification; those systems will therefore also not have the equipment for significant repairs, so pulling out the jump drive is not an option for them. However, that could work well for other worlds.
(The Book-2 design also used oversized drives - someone please explain why they needed C-drives to get PPl-1/Jump-1/Manuever-1 out of a 400 dT merchantman that was going to need to be subsidized - and left another 10 dT unaccounted for, so there's another 25 dT to throw into the cargo space if you call that errata and correct for those, not to mention bringing the cost of the subbie down. Official Errata calls that 10 dT "upgrade space", i.e. the 50-ton drive space of the standard hull is separate from the cargo bay, amounts to vacant space in the engine compartment, though I imagine the unused drive space could still be configured to stow some piecemeal cargo. There's room there to upgrade the power plant and bring the maneuver up to 3g while maintaining jump-1, or to take the whole set up to maneuver-2/jump-2.)
I'm very fond of the Broadsword fighter. (It's actually 6 dT; the Zhodani fighter comes in at 8 dT.) It would actually be my first choice for a cheap system defense fighter, but it depends on your rule system: 10 or 20 Broadsword missile fighters launching 3 missiles each under Book-2 combat rules can make a pirate very briefly unhappy - and then he'll be dead - but under High Guard rules, the fighters have to deal with the lack of a bridge, the resulting computer penalty, a size modifier and the target's agility. That can all add up quick, resulting in the little fighter needing a 12 to hit a corsair, or possibly having no chance at a hit, depending how the Corsair's armed and how much power it has available for agility.
The 10dT fighter has a bridge and computer, as far as I know. A bridgeless Book-5 TL 9 10 dT fighter has quite a bit more room (about 3dT) left for armor or other mods, a TL13 10 dT fighter can manage bridge and computer with a wee bit of space left over, and a TL15 10 dT fighter can manage bridge and computer with 0.7 tons of space left over (which is pretty close to the Book-2 version). That little edge can triple its odds from 1 in 36 to 3 in 36, or give it a small chance to hit where the Broadsword fighter had no chance.
If using Book-2 combat, the Broadsword fighter is the fighter of choice. If using Book-5, the standard 10 dT fighter is preferred.
The other option is to construct a "dispersed structure" that allowed fighter basing, that fit into the Type R's hold.
Upon reaching station the whole structure, fighters and all, is launched; this allows all fighers to then all be launched in a (subsequent) turn.
The Supplement-7/Traveller-Adventure subbie has a 7.5 meter wide, 6 meter tall bow door, a 13.5 meter wide, 6 meter tall stern door, and a 45 meter long, 6 meter tall bay. As layed out, the cargo bay actually fits 250 dT - the usual slight inaccuracies of Traveller deck plans - so one needs to be careful of going by the canon plans. Nonetheless, one can probably manage something in the neighborhood of 150 or more dT in a purpose-built construct designed to fit into the cargo bay.
"Dispersed Structure" is a Book-5 concept, so the Book-2 construction rules wouldn't apply and you'd have to figure out the base tech level of the construct to figure out how much space is available for your fighters. Still, after a bridge and a small power plant and drive (it isn't really a tender unless it has the necessary equipment), you could have something capable of launching and recovering the entire brood in a turn. Problem I can see is it's adding quite a bit of cost - MCr14 to 21, depending on tech level - for the privilege of being able to rapidly deploy the fighters. For the added cost, I think you'd do better buying a purpose-built pocket carrier rather than buying a subbie and having a tender specially built to go inside it.