Sure! It’s under GPLv3 so you can fork it and make a PR whenever! I haven’t worked on it since early 2017 but I would love it if you contributed! If you have any questions about the code or anything I can do my best to answer!
For the procedural part, I cleaned up the code a bit not too long ago, but the version I had started implementing was procedural terrain with 2d Perlin Noise, but the result wasn’t very interesting. Maybe you can try to push off from there?