You can't convince me that people that can make ships fueled with antimatter and are capable of FTL travel, can't use relatively simple planetary heat management solutions that are in theory possible to make with current IRL technology.
Honestly, that sounds more like a "you" problem than an issue with the mod.
It's a problem of people only providing bad excuses for why X, Y, or Z can't be done when far harder things are done regularly in the same setting.
With the technology of the game's world, even in the state the game's universe is in, cooling a Venus like planet would be a simple, even if time consuming task, and many planets would be even easier to cool since they don't have thick atmosphere's trapping a lot of heat and would instead radiate it directly into space. All it takes to make a planet colder is to make it absorb less heat than it radiates into space, it would work for literally any planet in existence, and it's exactly why moons like Io are colder than than the Earth's moon on the surface, Io doesn't absorb enough heat to have a higher surface temperature than Earth's moon.