Anyway im interested in design systems because traveller is one of the only games where it matters. Different planets doing different things. The fleets of the imperium facing the fleets of a pocket empire or an alien race with radically different designs.
But it doesn't really matter.
Sure, you can make any kind of design you want, but in the end, it's the weapons that matter, and Traveller's variety is pretty limited. Lasers, Missiles, Energy Weapons, PAs and Mesons.
Countered by dampers, meson screen, repulsors, and armor.
And of those, the Meson is the deal breaker.
Compare to SFB: Phasers (I, II, III, IV, Gatling), Photons (N[ormal], Proximity, O[verloaded]), Disruptors (N, O), Fusion Beams (N, O), Hellbores(N, O, Direct Fire), Plasmatic Pulsar Device (N, O), Drones (vast array), Plasma Topedoes(F, G, S, R), Plasma Bolts, and whatever it was that the Adromedans used (essentially a PH-IV). And I have no idea what the more modern races offer.
Then you have the other systems: Tholian Web, Tholian Web Casters, Expanding Sphere Generators, Stasis Field Generators, Cloaking Devices, Engine Doubling
Those fleets and ships were design around the weapons they carried, the doctrines they practiced, etc. There's racial limitations to systems and their use (some of the weapons are very powerful). Klingons and Kzinti are both rely on Disruptors and Drones, but the ships fight completely differently.
The point being that in Traveller, you can make all sorts of different size boxes, but they all hold the same, limited stuff, so in the end, there's really not that much variety.
And yes, I understand they're completely different games, but the point remains that despite the free form nature of ship design, in the end, (i.e. in game combat), there aren't really that many decisions to make that matter.