Pretty much everything above Z1 is a VO2max interval. 
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I think you are misunderstanding VO2max workouts (or we’ve a comms problem).
You can’t just look at an individual interval you need to consider the VO2max workouts as a whole. The recovery intervals and their duration are as important as the work intervals themselves. Do an isolated VO2max interval of two to three minutes at 120% and it’s unlikely that your systems will have actually reached VO2max, there’s a lag.
So if you did a three minute VO2max interval, recovered for thirty minutes then did another you are effectively back at square one for that second interval. Now look at some of the VO2max workouts, they aren’t like that at all. They are short efforts with short recoveries. The point being to not give the body time to recover and therefor deal with that “lag”.
The Baird series is a good example. Baird itself is composed of three sets of five by one minute intervals with a minute’s rest between them. The first interval you won’t be in VO2max but you won’t recover fully by the end of the first recovery interval so your second work interval will see you reach VO2max at some point. Again you won’t fully recover in the next valley but crucially you won’t recover as well as you did in your first so the third work interval will see more time at VO2max. This repeats throughout the set so for the last couple of intervals you are probably at VO2max for the entire minute.
Baird+1 reduces the recovery intervals to 30 seconds so you get to VO2max even quicker. With a workout like that it effectively becomes an over-under session but at 120%-110% not 105%-95%!
So why not always do the full three minutes at 120%? Well it takes time for your body and brain to adapt to this sort of workout. Look through the plans and you’ll see a progression in stress as you get used to the effort required. As an example: Sweet Spot Base Low Volume 2 has VO2max workouts with intervals of 30 seconds, one minute, two minutes and finally three minutes.
Listen to podcast 252 from about 42mins where they go through the whole reasoning and science behind VO2max.
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Yes, the recovery time matters, but unless it is really short, you’re basically starting over each time. Even with only 30 seconds of recovery between efforts, you still need to keep the intensity really high, or else recovery will be too much.
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@old_but_not_dead_yet from the article you linked:
Based on this, the workout would be expected to place a sufficiently high demand upon the cardiovascular system to be considered a VO2max
and
the short rest periods and especially the relatively high intensity at which they were performed constrained the power the rider could produce during the work periods such that their anaerobic capacity does not appear to have been significantly challenged
two systems:
- cardiovascular
- metabolic
The first was challenged by the 20x 30/30s. The second did not have a strong impact on improving anaerobic capacity.
it concludes with:
Applied to a typical 30 s, 30 s off series of intervals, the approach demonstrates why such intervals are so commonly used to prepare for the constant, “on-off” nature of criterium racing, which tend to place greater emphasis on neuromuscular power (e.g., jumping out of turns, launching attacks, sprinting at the finish) and VO2max (e.g., chasing down breakaways) than on anaerobic capacity or functional threshold power, both of which are called upon during more extended efforts of somewhat lower intensity than typically occur during criteriums.
To paraphrase that summary of 30/30s:
- good for developing neuromuscular power
- good for developing vo2max
- and doesn’t do much to develop anaerobic capacity or power at threshold (FTP)
Going back to what you said:
my read of Allen’s analysis of the 30/30s, and it seems your statement applies to anaerobic capacity. In other words, if you want to improve anaerobic capacity then go with a longer interval format or intensity. Its one reason why you don’t just do 30/30s.
On a related note, this was an interesting read: High-Intensity Interval Duration - Joe Friel
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How many people here do their “recovery” periods at ~85% of FTP, like that guy?
I would wager none, which means VO2 would decrease substantially during those rest periods, and then would take some amount of time to increase again. From what I have seen, then, the shorter intervals that many here seem to call VO2max efforts, actually aren’t.
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Ever done short power build mid volume? Here are 3:
care to wager again? 
On a serious note, high-intensity intervals have been studied a lot and I believe exact results will vary depending on the individual, current fitness level, and how you perform the short intervals.
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I’m doing one next week. I’ll let you know how awesome it is. 
That’s one workout in the library. How many more can you list?
Yes, that is a challenge. 
Then I suppose you would have to ask how often people actually complete such workouts, but let’s start with the above.
Sorry, misread your post. Let’s start with the second question.
In regards to the w/o I posted…a cursory scroll through the ‘All Rides’ shows a lot of completions – at intensity. 
Challenge is yours… lots of people do short power build. There is no single vo2max workout, there are several types. You linked a Hunter Allen, he listed out several objectives of that type of session. Workouts often have a primary and several secondary objectives. For example to help satisfy your curiosity go read the 4th paragraph under Goals for Taylor -2 which is a 30/30 workout in SSB-2 LV and MV.
Well then I stand corrected. I just keep seeing people refer to 1-3 minute intervals as being VO2max efforts, without any mention of the rest intervals. Since it takes 2-3 minutes just to reach VO2max, it at least makes it seem like a lot of people aren’t getting there.
Oh well. We can’t all train in a lab hooked up to tubes and machines. Not sure even pros do that. So I guess we just do what we can do. Maybe you could hit up the Workout Creator and post up what an actual true VO2max sesh should be. 
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What’s wrong with doing 3-5 minutes intervals, with roughly equal recovery periods? That’s what is prescribed in textbooks, and seems to work best.
Kaiser +2 (9x3 min at 120%) provides 20 min at VO2 max (according to WKO). And to continue the discusion, if there is sometning about VO2 max, this guy writes about it:
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What’s wrong with doing 3-5 hour endurance intervals? That’s what is prescribed in textbooks, and also seems to work best.
Waiting for that perfect VO2max workout…
There’s nothing wrong with them. Look at the back half of the Century Speciality to see them in action in TR plans. They’re just not the only way. I’m sure one can find studies that show that any one of the options is “best.”
I’m not talking about TR workouts, I’m talking about what many here seem to mistakenly believe.
Look no further:
A total of 334 subjects from 37 studies…published in English from 1965–2012