Hey, Dale!
That's what the little delta-shaped foam neoprene pad under your schnozz is for on the PMP wide view. Just wrap your thumb and forefinger around the exhaust valve housing and push straight up - does a great job of blocking both nostrils for a valsalva. Any-one who used one of the original wide-view masks with the hard-rubber seal knows how easily they leaked - since the hard edge wouldn't flex to follow a grin, grimace, or a beautific smile if you just spotted a big yellowtail in range! So that's why the big exhaust valve - any water in and even a slight snort would clear it! When the soft wet-suit material seal came on the scene, the honking big exhaust valve wasn't really neccesary any more - cuz the mask sealed well (not like a Squale, of course, but pretty darn good)but everybody liked it - the molds were paid for - so, if it aint broke . .etc.
I was a real fan of Art B. Everything he made worked very well - just as you expected it should - from seamless front-entry shorties to Duck feet. He should be canonized for Duck feet alone! I still use them. Even his snorkels with the weird little mouthpiece - like a baby pacifier - worked well, just looked a little strange.