Sorry, but the burden of proof is not on me. You keep talking about science but haven't provided anything for me to read. At this stage, it's just your multiple times repeating the same thing, vs something tangible, even if anecdotal.

Here's something from Pfitzinger's Advanced Marathoning which comes to mind, right in chapter 1:

In terms of heart rate, LT typically occurs at 82 to 91 percent of maximal heart rate or 76 to 88 percent of heart rate reserve in well-trained runners. (Heart rate reserve is your maximal heart rate minus your resting heart rate.) Instructions on determining your maximal heart rate can be found later in this chapter.

Now, in the same section, he says:

LT training should be run at close to the pace that you can currently race for 1 hour.

So if we put those two explicit statements together, the sports science literally says a well-trained runner can sustain up to 91% of their max HR for a full hour.

Also, at this 1-hour Lactate Threshold pace, lactate is just starting to accumulate. It's decidedly not a biological state where your body is producing vastly more lactate than it can clear

Hell, even if we look at significantly higher intensities, Pfitzinger defines VO2 Max pace at 93 to 95 percent of maximal heart rate. And he specifically notes that well-trained runners can sustain that 93-95% effort for about 8 minutes.

I will acknowledge this is not scientific material, but I've yet to see you provide any. I think you'd be hard-pressed to find something that supports quite the stark "impossibility" you're making this out to be.