I have been a BattleTech fan for over 25 years and when Harebrained Schemes released BATTLETECH, the first thing I looked for (after battering my way through the campaign) were mod tools for map making. No luck - their environment pipeline is heavily tied into their in-house Unity workspace. I talked shop with their Env Art Lead over sandwiches and drinks and they would love to put map modding into the public's hands, but the workload to make it happen isn't practical.
So I scratched my itch to make a new environment for the game anyway, in UE4, over the course of a weekend (about 18 hours or so of work). This environment was just a small vignette designed to mimic the look, feel, and fidelity of their environments, minus some gameplay elements that they add in their editor.
Don't shoot the floating spheres, they explode. Also don't drink the water. The air is toxic too. Maybe just stay in orbit.