Thanks for starting this conversation and I hope others will join in. Sounds like you have put a lot of thought into your training and the assessment thereof. I have one immediate comment regarding the hill sprints. These are meant to develop specific leg power for climbing up steep terrain. They are not meant as an endurance workout. From the sounds of it you are running uphill as hard as you can for 300 meters?? Wow that will be a gut busting workout. If this is what you are doing, that is not the intended Hill Sprint workout. The duration of these Hill Sprints should be no more than 10 seconds. This way the intensity of each repetition can be maximal when separated by a complete recovery of 3 minutes wherein you slowly walk back to the starting point and rest there. If I interpret your description correctly you are sprinting uphill 300 meters which must take at least a minute. This will be great for building anaerobic endurance which could be super useful for someone like a 400 or 800m runner but will have minimal transfer to your ‘event’ of climbing Denali.
Most everyone who does the Hill Sprints feels local muscular fatigue, stiffness and maybe some initial soreness but you should not feel like puking during these. The duration is just too short to elicit much HR response which is why we recommend disregarding HR as it will not be a useful metic of effort.
I hope this helps. If I misinterpreted your Hill Sprint comment, sorry.