Emin Boztepe might have a better physique than most Wing Chun practitioners, but if you've seen the video footage of his fight with William Cheung, (another Wing Chun Master,) the only logical conclusion is that he'd have gotten his ass kicked in the UFC. Cheung was much older, tricked and then sucker-punched, and it still just ended up being two seemingly-unskilled guys attempting to wrestle. It's a helluva coincidence that between two of these well-regarded masters of Wing Chun, neither apparently had the "real" Wing Chun.
I actually really liked a lot of Emin Boztepe's demo videos. They were cool and well-produced, like movie fight scenes, (and about as realistic.) And I actually kinda understood his side of why he never did business with the UFC, (he actually wanted to fight RORION specifically moreso than actually wanting to fight in the UFC.) But if he wanted to fight somewhere, he could've. He didn't. I just read about Gary Goodridge and how he got into the UFC. He called their marketing department and eventually got to Art Davie, and boom, he was fighting in the UFC. That's a guy who wanted to fight.
I never heard of Boztepe wanting to fight Vitor or Frank. I thought his war of words with Rorion well preceded either of them. Royce would've submitted him easily, but Vitor or Frank would have killed him.