You can trim the beards down to get good fit. They can be as long as 10mm and not have any material impact on the fit of the mask, so long as you use the right

You can trim the beards down to get good fit. They can be as long as 10mm and not have any material impact on the fit of the mask, so long as you use the right mask-fitting process. They may be harder to fit on someone with a 10mm beard, but it’s still do-able. Same with CPAP and SCUBA masks.