When you said it like that I assumed that stubble and chinstraps would be fine, since they aren't beards in my mind. However according to the chart, they will

When you said it like that I assumed that stubble and chinstraps would be fine, since they aren't beards in my mind. However according to the chart, they will interfere with the mask. The chart is the best. It answers all questions, requires no reading, and also lets you figure out how to modify your facial hair to be "good".