Personally I would change it to the below. A fairly small change, approximately doubling the overall number of ores in each chunk, while making it significantly more likely for you to find at least one.
Siminsions=-1
I:"Dungeon Loot Amount"=0
I:"Dungeon Loot Chance"=0
I:"Max Height"=128
I:"Min Height"=0
I:"Vein Chance"=100
I:"Vein Density"=100
I:"Vein Size"=1
I:"Veins Per Chunk"=12
I:"Dungeon Loot Amount"=0
I:"Dungeon Loot Chance"=0
I:"Max Height"=128
I:"Min Height"=0
I:"Vein Chance"=100
I:"Vein Density"=100
I:"Vein Size"=1
I:"Veins Per Chunk"=12