I’d be curious to hear your results with the following:
* First, at your home elevation, find a cadence-ventilation rhythm at Z1/2. For flat running, something like a 10-cycle (breath in five steps, out five steps) or 8-cycle is a good place to start. For hiking, a 4-, 5-, or 6-cycle is a good place to start.
* Second, at elevation, use the same breathing cycle, note your HR and whether or not your RPE is similar.