I just listened to the podcast covering the Hepox device and the whole time I couldn’t help but shout that fellrnr had published this quite a while ago. The guy on the podcast says that he thought of the idea and kept it to himself while racing, but fellrnr published it online for everyone to use back in 2015: DIY Altitude Training - Fellrnr.com, Running tips
I can’t imagine he’ll get the patent given this…
If the device helps people and makes it more accessible, good for them, and maybe I’ll even try it, but I just felt like the credit was missing here.