Most other ore related mods generally contain the ability for the user to define custom parameters for the generation of ores, the following is just a diamond ore example pulled from a Nether ore mod.

{
"diamondOre": {
"diamondMinHeight": {
"comment": "Set Diamond Min Spawn Height (Default: 90)",
"value": 90
},
"diamondVeinSize": {
"comment": "Set Max Diamond Vein Size (Default: 8)",
"value": 12
},
"diamondPerChunk": {
"comment": "Set Diamond Spawn Chance (Default: 3)",
"value": 8
},
"diamondGeneration": {
"comment": "Generate Diamond Ore",
"value": true
},
"diamondMaxHeight": {
"comment": "Set Diamond Max Spawn Height (Default: 125)",
"value": 125
}