Haven’t had a lot of time to look around yet so I’m wondering if anyone is sitting on any nuggets of info on how to possibly change how the world is generated?
The relevant files seems to be in services/server/world_generation.
Would love to have larger lakes/river like features.
It sounds like you are looking in the right area.
I’ve heard during streams that they have an intern looking into adding Biomes to the game. So sometime in the next few months we could see something new there.
There is certainly room to do your own thing in the meantime though.
I’ve found that messing with the /services/ files can be tempremental, so make sure to test every change you make in the microworld 
I’d be very interested to see what you can do!
I think that they’re trying to get rivers into the game, because currently we only have lakes. I’m also waiting for the biomes system.
Sometimes there are huge lakes, if you get lucky with your world seed, but I guess you want something different 
And welcome to the forum, @spacebar 