add:
I was watching the video under this link about training ME: https://uphillathlete.com/vertical-beast-mode-what-is-muscular-endurance-why-it-is-important-for-any-alpinist-or-mountaineer-and-how-do-you-train-it/
the speed of the ME training would set me quickly far above a conversational heart rate and I would struggle with my ME and heart rate.
Generally I realised to be slower on the mountain than other climbers, but consistent.
I think it comes back again to train my AeT, increase my speed and lower the general bpm.