Feature request: Aerobic threshold/Efficiency factor metric

I was reading this blog post on training peaks: https://www.trainingpeaks.com/blog/tracking-aerobic-threshold-training-with-wko4/

It seems like zone 1/2 recovery rides/long-slow distance on the trainer should be perfect data for such a measurement. E.g. Flecter

This kind of tracking is important for me because I do 10+ hour races. Ultimately, I want to maximize my power at VT1/aerobic threshold for these long efforts, so that means I want to track my efficiency factor(EF) to make sure I’m getting the most out of my aerobic work and that I don’t lose any substantial aerobic fitness while I put in some high intensity in the lead up to my A races.

Quoting from the article:
“This is where the Efficiency Factor (EF) metric comes in … EF is the Normalized Power or pace for a workout divided by the average heart rate for that workout.”

TR advocates against using HR as base for your workouts, so I don’t see this being integrated.

(Nevertheless I’d like to see some form of HR/Power correlation/drift metric with ride data but it’s probably not coming.)

On the other hand much more I’d like to see MPA / W’ Balance being implemented.

For now, for both metrics we need to use other tools to analyze (for example Golden Cheetah).