For example, Custom Ore Gen is very interesting mod which help very much customize your modpacks. For example now, I create TerraFirmaCraft+GregTech modpack, but I can't use cog because it's to hard and unstable. Integrate please lite version of this mod in Mantle, for example, it doesn't have custom gui and all configuration are in config file. You can disable vanilla ores and ores from mod and for example something like this (config file):

VeinName(###)
Biomes:###^#, #####^#
Ore:###^#, ###^#
Height:###^###
VHeight:###
Area:##
Mass:###
Density:###

VeinName(GalenaOre)
Biomes: ExtremeHills^60, Forest^40
Ore: Galena^70, Antimony^30
Height: 40^80
VHeight:8
Area:3
Mass:40
Density:2

What this means? This means that in world will be generated ore vein with name “GalenaOre” with frequency 40/(40+n)*100%(“n” is mass of other veins). It will be spawn in biome ExtremeHills with frequency 60% or Forest with frequency 40%. It will be comprise 70% of Galena ore and 30% of Antimony ore (users must write in this pole id of some ores). It will be spawn on height 40-80(with the biggest frequency in the middle). Height of this vein in blocks is 8 and it will spawn on area 3^3. His density will be 2 blocks of ore per one block of cobble. All veins are cubic. In addition, if you choose to do so, please add this feature in previous versions of Mantle.