Actually, I found that face-fucking is one of the more common things a provider will do, compared to other shit. I am never shy to ask for whatever I want. Some providers make a funny face if it's really disgusting, and I just tell them they are in the wrong business if they cant even tolerate being ASKED.
I remember hanging with slinky at a place thats since closed, and two girls were trying to sell us VIP. I told them I was in the mood for something freaky and we ran down the laundry list of stuff I'd like to do or have them do to each other. Face fucking was the one thing that sold me that they were willing to do.
I think you guys are seriously underestimating women's possibilities for kink in general if you think THAT is a big deal. Especially among providers, many of them get bored out of their skulls doing the same suck-and-fuck routine. In many cases they actually appreciate a chance to do something a little more challenging and show off their 'skillz'
As for on tape, the best scene ever is Shyla from Slap Happy 1. They actually toned it down after that because they were worried about prosecution, those pussies!