Cycling Base vs Build if Z2 is not priority

Before we even start, please don't tell me base should be all Z2. I've done a lot of research and believe that zone distribution is all about your goals and ability to recover between workouts. With minimal time, Z2 is not the most efficient for me and I'm trying to get a better understanding of what that looks like in similar athletes.

I get the basic idea of the difference between base and build (base = aerobic and muscle building, build = race-specific structured intensity).

I have about 10ish hours a week to train and am doing ~5 hours of cycling per week. So because of that time limit, I'm doing 1 VO2max interval set, 1 sweet spot ride, and 1 easy outdoor long ride with some hills a week. Feel like this has been great in the base - good balance of intensity and recovery and my power and distance endurance is consistently improving.

But! How the heck is this supposed to be different from my Build Phase? Would I drop off sweet spot rides and add more intervals or harder intensities? Or should I be doing slightly less VO2 max work in the base and add this in ~ 8 weeks out from my race?

TLDR: Z2 is not my priority but unsure how to apply time-efficient, intensity-based workouts to build vs base phase cycles.