Also, the reactor is "rotatable"; so, you can now optimize to a LOT of shapes. Below are a few very different but typical aesthetics that can be optimised:
The Klingon warbird has a short nose, but two long diagonal wings. You could put a reactor in the main body, and stabs in the nose and two wingtips, then rotate the reactor 45degress to get 3 fairly long vectors of stab efficiency.
The Vulcan halo nacel ships are way better than a doom cube. You can centralize your reactor and get 6 vectors for stabs without making yourself a super easy to hit high profile target.
a Basic ufo, or any other flat ship can easily get 4 decent stab lines with a central reactor. You could even rotate your reactor on the Y to make your stabs in less predictable places.
And for the warhammer 40k buffs: Many of these ships are pretty much longbois anyway, so, you could just go extreme front/back or you could add secondary stabs in those towers for a bit of extra redundancy.
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The bonus is calculated as if the reactor was a cube with six faces, but neither the reactor nor the stabilizer groups need be cubes, nor do they need to be orthogonal or equidistant to the physical reactor shape. In other words, build your reactor and stabilizer groups however you like while maintaining positive integrity, and use the Reactor axis controls for any oddities.
This is actually the exception which is that systems DO need to be cubes to stay stable. Building a ship to being exactly integrity stable is just as bad as building a ship that is not at all integrity stable, because once a bullet flies through it once, it will become unstable and start having chain-reaction explosions until it completely destroys itself; so, the meta is 100% cubes because they can take more deformation from damage before losing stability, than any other block shape.