Leaving these links.
Can the accuracy bias by facial hairstyle be reduced through balancing the training data? They conclude facial hair does degrade accuracy of FR, but only to a degree.
Also, The Significance of Hair for Face Recognition
But FR gets more sophisicated all the time. I would expect, as years go on, the accuracy loss from facial hair changes will grow smaller. SmallER, but not zero.
This avenue isn't so open to women or children tho, lol. Maybe the naqib users have the right idea. Just not for the reasons they originally thought. But that just begets France and others banning obscuration garments.