I thought of requesting this after watching a recent video of a mod called JJThunder's To The Max, and thought of adding Alex's Caves with it (which did not go well, unfortunately).

JJThunder's King of The Hills works kinda well, except the cave/terrain generation is mixed up.
Both mods interrupt the cave generation and both generate entrances to the other caves that are way too open, which kills off the hidden nature of these caves (If that's what I'm trying to describe here).