I am amazed that I have not ever heard of Pioneer, at the moment it is simple but brilliant in terms of flight mechanics, galaxy generation and the procedural generator is a good start. The best feature of course is the open source engine, I'm a concept artist and 3D modeler, though I also love to modify code, my favorite being C++. I am working on my own sci fi universe called Union, along with models for a Elite Clone, though first I am making the changes/improvements I need to the Pioneer engine first.

I'll keep this short because what I previously spent time was erased when my window refreshed. I'm working on adding in:
-New political factions, 73-74 in total, assigned to Left-Right Wings, Political Compass Quads and Grouping based on those you find in the Elite Dangerous BGS. Prepping for implementing a 2 way interactive BGS system (You interact with the AI, AI interacts with you and other AIs based on you actions)
-New Economies, various capitalist economies, Market Socialism, Mutualism, Planned Economy has been replaced with Communism. I have also created new enums for system monetary wealth and resource wealth (this may also be per faction and district/city/starport), with Communist economies having post currency and either Utopian or Shared Burden conditions based on access to resources.
-New Industries, most of them from Elite Dangerous.
-New commodities for the industries, almost 700 or more I have to finish coding.
-Districts for cities.
-Multiple factions per District/Starport, along with each starport/District being assigned an industry type.
-Populations are generated for every District/Starport, making up total population of a city/system.

Maybe at some point Pioneer will beat even Elite Dangerous to space legs 😀 .
If the dev team needs any help with coding, procedural generation, modelling or concept art I would be happy to assist. I registered for the Pioneer dev forum, though I am yet to get my confirmation, which is why I'm posting here.

here is my artstation:
https://www.artstation.com/arghouse