Regarding east african altitude conversions. There is peer reviewed research that ethiopian highlanders can maintain super high hemoglobin saturation even at high altitudes. (This is the finger tests that some of you have probably done for covid) This means that through genetic adaption (living at high elevation for millenia) ethiopians (and probaby kenayans) are not as slowed down by altitude. Even more so that the average european that has lived at altitude there whole life or for years. There are obviously outliers (look at matt carpenter) and maybe young is particularly well adapted also.
obviously they would never have different conversion times for different races (as you would have to scientifically prove that higher hm saturation translates to running performance). But it is very interesting research.
An Ethiopian pattern of human adaptation to high-altitude hypoxia
Cynthia M. Beall, Michael J. Decker, Gary M. Brittenham, +2 , and Kingman P. Strohl
We describe, in Ethiopia, a third successful pattern of human adaptation
to high-altitude hypoxia that contrasts with both the Andean “classic”
(erythrocytosis with arterial hypoxemia) and the more recently
identified Tibetan (normal venous hemoglobin concentration with arterial
hypoxemia) patterns. A field survey of 236 Ethiopian native residents
at 3,530 m (11,650 feet), 14–86 years of age, without evidence of iron
deficiency, hemoglobinopathy, or chronic inflammation, found an average
hemoglobin concentration of 15.9 and 15.0 g/dl for males and females,
respectively, and an average oxygen saturation of hemoglobin of 95.3%.
Thus, Ethiopian highlanders maintain venous hemoglobin concentrations
and arterial oxygen saturation within the ranges of sea level
populations, despite the unavoidable, universal decrease in the ambient
oxygen tension at high altitude.c