Whilst i don't know about the percentages, I do think there may be a slight truth in what the OP says about lesbians being able to compartmentalize this easily. Know a lot of girls in porn (certainly American girls, though Kiesha Kane was queer from this country-sure there are plenty more) in real life, it's how they're able to do it. But that's on screen where its easier to say it's "performing".
And yes, whilst there are still plenty of butch dykes who are chubby with short hair and man's clothes, there are lots of very feminine, but very very gay, and very beautiful, totally unidentifiable, long-haired feminine lesbians too. It is 2017 after all