I had an idea regarding power generation that could be simple to add but creates interesting choices.
Industry and research require power to operate efficiently. Normally this cost is included in the wealth cost to operate. However, a planet, or even a moon, can have a natural occurring power source. These pay for a set amount of industry as if they were nearly free. For example, Venus has a high-pressure atmosphere which can be utilized into a power source. The amount of energy is quite high and thus can handle a large amount of industry on its own without an energy grid built for it, and environmental concerns are very low.
Thus, a harsh but high energy planet might be better for the industry but not as livable compared to other planets. Players would choose which is more valuable for them to develop. Something to consider in the future without adding too much micromanagement.
Power tech will improve the bonus to natural occurring power making it cheaper to operate a factory/lab.
With this one could actually create a "high energy planet" using terraformers with Venus as en example, giving
terraforming another use besides changing a planets surface into a liveable environment.
Stars could also become major power sources by collecting light with mirrors, powering the rest of the system by beaming it over as a laser, which could also double as a powerful weapon.
Light still has travel time though, so you'd rather beam it to a nearby planet or space station and then redirect it toward the invaders.
Another possibility would be star lifting.
With mirrors again you'd reflect the light back to the star, blowing off material at its poles.
While feeding back elements the star needs for fusion you filter out impurities, among which could be valuable minerals.
The rest would be sold to the civilian sector, generating wealth.