I would argue that the Kletka Simulator is the only colony building in this mod that would require new physics or extreme technological advancements.
This got me thinking a bit, and I think I stumbled upon a pretty good idea.
The primary obstacle in creating virtual realities realistic enough to fool even Alpha Cores is the absurd amount of computation required. The resource for computation is energy, each bit flipped generates heat, and a good heat sink allows more computations per joule. Landauer's principle.
Now, even if we're generous and assume that the Kletka simulations are good enough to trick the AIs without having to recreate everything at the atomic scale or below, they would still be so taxing in terms of computing that you would need a really,
really potent heat sink to prevent the energy consumed by the computations from being so absurd it could cause planet-wide blackouts, and that would be the lesser of your worries, since the extreme heat generated would be melting the computers or even their host stations.
With that in mind, I think Kletka Simulators should receive a treatment similar to Industrial Evolution's Supercomputers and be completely limited to cold worlds. This would:
1. Be more realistic.
2. Make it harder to spam them and get obscene amounts of cores, effectively nerfing them without doing any real damage to their viability.
3. Incentivize creating tundra and frozen worlds.
The only negative to this I can think of is the inconvenience it would cause to certain oddballs that I'm not sure even exist. By that I mean those who use this mod's Kletka Simulators, yet disable terraforming. Seeing that the primary reason why anyone would do the latter is the clash with Starsector's current lore(terraforming being like a lost art and all,) I can't imagine there being many among them who would use the far more egregious offense against the lore that is the Kletka.