Feature Request: Rucking with a weighted pack.

I also want this feature. I am getting into rucking and other forms of weighted walking such as carrying a sand kettlebell while walking and doing various exercises with the bag/bell or walking with  heavier sand bag. 

Wouldn't there be a need for this for accurate VO2 measurement? 

If your watch has an expected exertion level for given activities, then adding 50 lb to your back would throw it off. If it sees you working much harder for a hike than it expects because it doesn't know you're carrying weight, it might perceive your fitness level as worse than it really is, and consequentially assign you a VO2 max score lower than your true level.

Is this not the case?

You just solved a puzzle for me. Garmin connect is telling me my vox is 33 and that I'm in the bottom 15% of 49 yo men. And at the same time my fitness afe is 47. My resting heart rate is high 40s to low 50s and I can bend over, pick up a 90lb bag of cement, throw it over my shoulder and hike it up 3 flights of stairs without breaking into zone 3. Sooo whatever

An option to add carrying weight to hiking or rucking activities is a fantastic idea, assuming corresponding algorithm(s) that adjust health and activity metrics in response to the activity. "Just add a note to the activity" is not a serious response. Carrying 50 pounds up and down a mountain, for example, would surely affect how health metrics are calculated.