The feature I liked most about BotF was, that colony ships where able to terraform uninhabited planets. My suggestion: Create a terraforming module (support, civilian) that can be added to any ship design and enables that ship to terraform a planet from orbit. Maybe this is just working on uninhabited planets but the feature would be even cooler if it worked like the terraforming on the system build queue

Rationale: In later game, when I have the technology of terraforming, there are systems that need very long to get to terraformed planets (as terraforming is understandably expensive). One could also use such a ship to reduce unhappiness of invaded system.