Looking for code pieces of map generation

[TroDie]

Hey, trying to make custom world generation for myself to play on. If anybody knows by any chance where to look for specific changes to:

AddRoom - "BGNoise",is one the most exciting room for map generation ("MoonIsland_Mine"/"MoonIsland_IslandShards" does something similar with lesser visual and gameplay impact), as it somehow makes holes in ground tiles, surrounded with turfs (in order) cobblestones, stones, light grass. How to learn this power to make maps more chaotic looking?

Next,

"Rivers". It always bothered me it disjointed task sets with impassable walls, but now boats came along and new annoying thing came up, you cant really sail in these canals without wrecking. What part of the code disjoints task rooms, is it possible to widen it?

non important annoyance - when generating islands, can generation make less obvious visual connection of a island to mainland, as it already quite easy to find moon island, day one of expansion release..

[Serpens]

Although I made some worldgeneration mods, your questions are also beyond my knowledge. I also dont know a tutorial beside the ones you find locked at the beginning of this forum part, some of them written by me.

So I would suggest searching the workshop for worldgen mods and see if you find something useful.