Geolosys-1.12-1.2-alpha
forge-1.12-14.21.1.2406-installer-win

I was trying to adjust the values of the spawning in my test world, and something just wasn't right, so I reset it all and just focused on the Hematite. I only changed the line:
I:"Hematite Pluton Chance Per Chunk"=
at 1 I wasn't able to find any, which is fair enough. At 100, I was getting maybe 1 Pluton/Vein per 50 or so chunks. Certainly nowhere near the 1 Pluton/Vein per chunk that a 100% chance should have given me.

Oops, I need to remove these configs as they're no longer valid since I made the change that only one vein spawns per chunk. And no - I won't make that configurable, that's simply a mechanic of the mod that is how I plan to keep it.

I'll be removing the unused configs now though :)

Thing is that I'm not getting 1 vein per chunk - i'm getting maybe 1 vein of something per 100 chunks. No way are people going to get enough iron to play the game that way.

I've actually been testing in my modpack for my server and I definitely have enough iron. I had to run 157 blocks from home to get it, but I did :)

You're not guaranteed exactly 1 vein per chunk. It's all based on chance.

This is a picture of a 14 chunk x 17 chunk hole I dug with Minestripper. That's 238 chunks or 60,928 blocks. It has 6 nodes in it all up, 2 of which contain iron, and only 1 of which had a sample on the surface. Ie. 1 in 40 chunks has a node.

By the time one of the players on my server manages that 60,000 to 1 shot of finding the sample, I will long ago have expired from all the complaining.

So, while this mod was sounding pretty good for us, I guess we're going back to funores with the biome specific spawning I worked out for our last server world.