So basically the CDC is saying no hair if it can potentially come between the respirator and the skin, basically? (Cursed thought: What if you had a full beard except you shaved off the outline of the respirator itself?)
While the British study seems to indicate you can get away with slightly more than stubble-length facial hair without compromising the efficiency of masks?
I may try to see what happens if I trim it down to the 2-3mm range. I will probably mess up and just shave the whole thing off though.