So, my thoughts on the options so far:
Excavator: New mechanics, but finding the right "veins" could be annoying. Especially if "no mineral" samples are as common as my test world seems to suggest. Also, I'm a bit late to be getting into steel making given how slow I remember it being.
Quantum Quarry: Requires me to have beaten both the wither (nether star) and Ender Dragon (Chorus Fruit for end rods)
RFTools Builder: Probably the best option since it does large areas and can have fortune or silk tourch. But I've used it before.
AA Vertical Miner: Pretty decent mining area (seems to be 2x2 chunks with max phantom upgrades), but no silk touch/fortune option, unless it inherits the drill's upgrades somehow?
BM Rituals: Again, used it before, plus getting far enough into blood magic to use it, much less get the setup needed to fuel Fortune, would be a pain at this point (I haven't done anything with blood magic this playthrough since my last playthrough was very heavy on blood magic).
Botania: Doesn't really seem suitable for large-scale operations. With the additional issue of no good long-range mana transport and no fortune/silk touch (as far as I know), probably the weakest option.
IE: Haven't played with this in a while, wasn't a big fan of the mod last time I played with it, and I don't want to set up a second power grid just to support a single mining system. The advanced miner looks cool, but expensive and annoying to build anyways. Also, it's slow. Veeeeery slow.
Ok, let's slightly expand the question: Are there options that are in mods not included in the DW20 pack?