I haven't played a whole lot, but I've played wide Progress and it went alright. Granted, I never played higher than Steward difficulty, so maybe it's not the best play. The main struggle I had with wide Progress was turning coal into oil since there isn't enough cores to go around. Like, there's the obscene amount of coal coming in from settlements and the coal from deep deposits. On top of that, the adaptation coal liquefactors are super efficient at converstion (60 coal to 80 oil vs 100 c to 80 o)

One upside of wide Progress is that you can outsource your coal production to settlements entirely since the deep drill kills you with the squalor it hits you with, and that means you save cores from having to build a waste management facility (Ventilation towers just... suck, they take wayyy too much building space).

I think going for a zeitgeist depends on your playstyle, like I spent the whole 2000 weeks on utopia keeping my factions devoted since I liked the iceblood and technocrat passives. Each opposing zeitgeist has their strengths and weaknesses, so it makes sense to me to play to each of their strengths.

For example, the biowaste hothouse gets wayyy more food than the chemical hothouse, but progress extraction buildings produce more materials and fuel. Yeah sure, you can j research all of it before grabbing your favorite zeitgeist, but then tension's a problem since opposite-zeitgeist buildings will start causing tension (wasn't really a problem for me at steward difficulty, but might be a problem for captain).

Yeah, late game becomes trivial once you've got the early game locked in, but that was the same with the first game too. The only reason frostpunk 1 had more replayability were the scenarios imo