So I wanted to make a "Rare" spawn of diamonds and being limited to yes or no it will spawn in a chunk is a little disappointing because I want this to be enough diamonds for 2 people to have full diamond armor and equipment and that many diamonds in every chuck would be game braking.

In short can their be a Percent that can be used or a fraction for "Spawn Rate" = #?

Spawn rate does not guarantee that many veins will be generated, spawn "attempts" is a more fitting description. Ore veins will fail to generate if the random block that the game selects is already occupied by something other than the chosen filler block. A very low spawn rate with a very low vein size would make that ore pretty rare.

That said, I can look into how emeralds and ancient debris is generated and add an option for generating rare ores similar to those.

ok sounds great keep me posted!

If you could keep a tab or something of "features" that users that want to go deeper into the possibilities for this mod and not just get it to skew how many diamonds spawn in their world.