Good stuff there.
I actually did Mills for the first time today. I replaced it with Dade -1 my first time through, and I’ll tell you, Mills sparks some ideas similar to what you linked. I dialed up Mills by 4-5%, starting the intervals at 125-126% of FTP, but ending down around 112% for the 2 minutes, and my uptake stayed right about where it should be for these types of workouts, but it was likely easier on my legs. I can see some real value in those “hard start” types of intervals for prolonged time at max uptake, but there’s probably a pretty fine line in terms of how much you can actually back off the power to achieve that and it’d vary from person-to-person.
It may be something I dabble with myself because I have a pretty good feel for my own personal VO2max efforts… I think it’d be hard to really program it for most athletes unless you’ve worked with them for a long time and can trust their feedback or are directly observing them during these workouts.