My map. My RSO settings.

I've been playing a Krastorio game and at first everything looked normal (green area on the screenshot), but then I placed a radar away from the center (near the blue "x" on the map) and suddenly there's way too much resources everywhere (red area).

By fiddling with the map generation settings and the RSO settings and recreating the chunks I was able to get more sane looking maps, but still it doesn't seem quite right. For example, here's the map after deleting the chunks roughly outside the "normal" area around the center and re-revealing them with all the vanilla map generation resource settings set to 100%, RSO region size set to 10, and RSO resource chance to 0.4. There's a Great Nothing to the north and then everything is kinda clumped together to the south.

Additionally, it seems like the mod barely cares, if at all, about the "resource chance" setting, the map only seems to look any different when I re-reveal it only if the region size is different.

My save from the first map. My save from the second map.

I took a look at first map and it seems that it's lucky. And it can be very lucky spawning multiple resource triggers that need about 0.07 to spawn. You can disable Multiple resources per spawn functionality to remove all those added and you'll end up with at max 2 ore patches per region (1 normal plus 1 added due to total amount of resources exceeding 10). Other then that settings you are trying are correct ones to reduce the resource density and rest is up to rng. It's hard to test based on few examples if rng became suddenly biased towards small numbers so for now I'd say it's working as intended.

Thank you for the quick response. I know that randomness can look non-random to the human eye, but what I had seemed quite extreme, like possibly denser than the default preset of vanilla. And consistent too, if I revealed more map it kept being too dense. Well, by fiddling with the settings I was able to get something that seems to look about reasonable (I settled on region 9, chance 0.3), so maybe it really is okay. I just don't remember having to crank RSO down so much before. Thanks again for the response, and the continued development of a great mod!