IMO this climb doesn't really do much to prove of xenon's effectiveness (altitude researcher Dr. Peter Hackett says as much [0]).

The team used supplemental oxygen on the climb, with the starting altitude and flow rate not being reported [1]. This is speculative, but if they were using more oxygen than typical and starting at a lower altitude, that's a massive advantage.

Further, Andrew Ushakov traveled from NYC to the summit in just under 4 days this year without the use of xenon (but also with supplemental oxygen with unknown starting altitude and flow rate). He used a hypoxic tent to prepare as well, and depending on the accuracy of the reporting may have even spent less time doing that than the xenon team did [1].

[0] https://www.npr.org/2025/05/18/nx-s1-5398553/a-new-company-i...

[1] https://www.alanarnette.com/blog/2025/05/21/everest-2025-fas...