Bonzo didn't need a port.
Depends on the sound they are going for
He’s not responsible for the quality out front live.
I don’t know any live engineer that likes no head.
For metal its usually a loose sound, doesn’t matter as much, its over-colored anyway.. For jazz, country, rock it matters. Bonzo did use heads on kick, they were probably just loose.
Studio is different, I’m live. What live engineers hate most is a kick head with no port.
Not at all saying his setup is wrong at all. No such thing as wrong, nor right. Just another idea he may want to experiment with.