Can’t speak for the OP, but I can dish out a sprint pretty close to max power at the end of a 6 hour ride.
The catch, however, is that I’d have to have been noodling for a few minutes prior to said sprint. Rarely would that happen in a bike race where the pace picks up.
So it has less to do with the hours leading up to the final power dump and more to do with last 5 minutes.
Such a neat model, I’ve always been curious what my anaerobic contribution is at 1-5 min. IMO, the OP should focus on building repeatability over max power @ 2-min. A crit is sort of like a CX race in that rarely does one huge effort win the race, it’s about the guy or gal that can hit repeated efforts and thin the field or be the last one to drop a race winning effort. It’s not like you’re noodling all race at Z2 and it comes down to a max-power sprint.
I’ve always done power/capacity first, then repeatability.
Curious…Why? I find that repeatability is what A) keeps me at the front of the group B) keeps me from being dropped C) allows me to make a move
I race primarily gravel and CX, the former is 100% a repeatability contest.
My premise is to start working on repeatability after raising power/capacity. Do I want a repeatable low power, or a repeatable higher power 
I dunno it worked for me both before and after TR.
I mean that makes sense. I think you can go both ways. Repeatability increases the aerobic contribution and in my experience has also lead to increases in raw wattage at a given duration.
So many ways to skin a cat!
The ability to recover and repeat is greatly enhanced by z2 and tempo work in my experience.
Interesting. Thanks!