Specifically, how does it work of you have the max Dynamax level? Does it use your new doubled HP, or your original, or does it not affect your HP at all like Choice Items being not locked into a move. Thanks in advance!
How odd, I found the answer to my own question. It turns out that Life Orb takes the same amount of health as if you weren't Dynamaxed. So, if you were at the max Dynamax Level, or double your HP, it would really only take 5% of your health, not 10%. Source: https://www.pokemon.com/us/strategy/dynamax-pokemon-battle-strategies-for-pokemon-sword-and-pokemon-shield/