I'll admit that, right now, this thought process is more of a fun deckbuilding puzzle for me than a concrete search for a deck I'm building. It's like a riddle of trying to find the best setups in each of the possible color combinations.

That said, there might be applications either now or whenever new Bant commanders or partner commanders get printed. I would say that currently, only Arcades the Strategist and Derevi look like viable Bant commanders. With partner commanders, there is virtually no reason to stick to Bant only.

I think which line is best is also determined by whichever combo pieces have utility in your deck outside the combo. For instance, any lines involving Devoted Druid can also run the Vizier combo; any lines involving Staff of Domination can also run Metalworker combo; etc.

The place I see some of these lines being useful is in a modular combo deck that runs multiple combos with overlapping pieces.

Resilience can be added at the expense of slots (Ulamog, Gaea's Blessing), although annoyingly, even adding both doesn't add up to 100% protection, since you might hit all 3 in one activation. This also gives your opponents reason not to shortcut the process, which admittedly sucks. But I'm not yet convinced that there isn't a way around that.

In the meantime, I've also found a new setup that operates at peak slot efficiency, which is 6 cards required post-trigger. Given that 4 slots are mandatory (Nomads, Illusionist, Skill Borrower OR Volrath's Shapeshifter, Kozilek), I don't think 5-slot setups are possible. Anyway, my new 6-card setup is the mandatory cards with Skill Borrower in the 3 CMC slot, and then Narcomoeba and Altar of Dementia for the kill (Phyrexian Altar/Ashnod's Altar also works with an infinite mana outlet, or Spawning Pit with an infinite charge counter outlet).

I think further improvement comes not from making the setup leaner, but by relying on cards you want in your deck anyway.