Next update is going to be "The Mining Update", and also a major overhaul.
Thanks to the multiple mentions about the Factory0 Resources mod, I posted some suggestions to the mod author, and he implemented them (amazing guy!). There is a now a "Burner Drill" - aka solid fuel quarry, plus also some more "tech" items for scanning the ores in a chunk.
As a result I'm looking at removing the existing quarry mods and use Factory0 instead, and revert world oregen back to almost vanilla.
Factory0 has two major advantages over using world gen and standard quarries, the first is performance and the second is getting the density required. I fired up Factorio and had a look at it's world gen. Normally ores are quite sparse, but in big clusters, and in a 16x16 area, you can have up to 512,000 pieces of ore! That's more then you can get in a chunk in minecraft, even with ore doubling and cheaper recipes with more advanced technologies still don't hit that level of density.
The other big change I'm implementing is removing Thermal Expansion, I'm using it for a few items/blocks (the rest are disabled), but all disabled items are still showing in JEI, which adds confusion to what are valid recipes.
I've also been looking at the Ecology Mod which introduces the concept of pollution. I'm still on the fence if it's really going to be worth having a pollution system, it's highly configurable, but unfortunately it doesn't affect dynamic trees (they love growing in acid rain!) but does have a feature that biomes convert into a wasteland biome, which I believe I can cause hostile mobs to spawn normally in with the In Control mod.
There be iron (and coal) in those hills:
Proof that you can get a lot of ore in this system (took a while to find these chunks) - testing continues.