If a Baal Tokea has a very full beard and moustache, is there a problem if hairs intercept between his lips and the shofar.

Piskei Teshuvos (586: 11) quotes R’A Shlezinger zt’l (2: 382) that the hairs of the moustache are indeed a ‘Hefsek’ or separation between the lips and the Shofar and should be removed. After the fact, when the blowing was done and some moustache hairs were separating, Horav Shlomo Miller’s Shlit’a opinion is that one complied with the mitzva.