Sweet preset. I was looking for something heavily mountainous for a dwarven-mountainhome-style playthrough, and this worked fairly well after a few tweaks. Namely, I:
- Changed the biome type from "All" to "Extreme Hills" (simple change)
- Bumped up the ore distribution massively, since with a few test gens, I consistently got moutains going up to the height limit, and I didn't want to have empty boring mountains since everything cool to find was below "sea level"! Namely, the ranges for granite/diorite/andesite/coal/iron were bumped up to [0,255], gold to [0,128], redstone [0,64], diamonds [0,32], and lapis to [0,64], with the spawn tries of each multiplied accordingly. This way there's proportionately the same amount of ore for a given y-level, just distributed to fill up the whole mountain.
As a result, I got a spawn area of snowy mountains and valleys worthy of the Longbeards themselves! (The seed I used is "khazad-dum", appropriately enough. (numerically, -1817781464) Only thing truly required for this is the "Extreme Hills only" biome change, the ore change is totally optional.) Like literally, just go a bit east of the spawn (watch your step, it is in the upper Y-200s here) and you'll
fall into find that canyon.