How to "learn" to do VO2 max

Honest question: to what degree it “wrong” to do VO2 in ERG? I feel like it is a valid approach. I’ve got a Zwift cog without those little blips for fake gearing, so I can’t ride in resistance mode (at least that is my understanding).

I’m curious what TR’s take on this is. I suspect a huge chunk of people ride in ERG mode only.

I do VO2 in ERG and if I fail a workout…I fail the workout. I figure that with ERG mode, I won’t be over-reaching the early intervals (e.g. with a “max effort”). Generally, if I am rested and well fed, I can complete the entire set of VO2 intervals, just barely.

Update: this seems to have been discussed recently here → What’s the goal of workouts like Baird+2?