You know what there is a lot of? There’s a lot of it’s not that, but not a whole lot of, it IS this. I could give a rat’s ass about mlss. I’m not measuring my lactate, and to be honest I don’t actually care. All it means to me is that for whatever reason above that line I’m making more lactate than I’m using. hizzah. Maybe I just need more NMN because I’m older.
I don’t care about what I ‘should’ be able to do, certainly based off flawed and pointless metrics in normalized distributions of cash poor college kids. If I want to know what I can do, I go do it. 
But the point, which sailed right over everyone’s head apparently. Is that people use these metrics to set their training, both within the eco-system of TR, and elsewhere. People are curious (and rightly so) about what value their training plans are using and whether one or the other is problematic. Again, I don’t care, I’m not going to do a workout that I can’t do, or one that I think is stupidly easy. I’ll curate my own plan because it’s quite apparent no system seems capable of it. I’d prefer not to be driven into a ditch by a coach or a plan that’s for sure.
So is tte for mlss durability? I’d argue if you can’t hold ~mlss for an hour you have a major durability problem so I guess…yes? Is that applicable to pros? probably not… So mlss is not durability?
And so we come full circle, it might be durability, but durability could be resilience, or it could be fatigue resistance, or…or… yeah yeah I get, no one knows what they’re doing. I’ll stop asking.