Just like in the new caves, bigger means you get around 20-30 diamonds per mining trip on average without fortune. It's insane. An option to turn/off a config to reduce exposed ore or just change rates of ores individually in config would be great for server-owners that want to keep it vanilla or slow progression or encourage strip mining for ores and caving for dungeons and fighting.

This is outside the scope of this mod. There are plenty of mods offering control over ore spawns already.

Can I get a name (for fabric) because I couldnt find any.

Not sure about Fabric, but at the very least you can modify the ore spawn rates yourself via datapack.