Very few are straight. Go to any adult bookstore that has peep shows in a backroom and you can see all the drag queens you want soliciting men for sex.
That's because that's where the gay ones hang out. Straight trannies aren't at the adult bookstores because there aren't women at adult bookstores. They're at the gyms demanding to use the showers. "Caitlyn" Jenner wasn't gay. A lot of them aren't. In fact, there's a debate among gays (largely hidden from us normal people) on whether 'LGB' should even include the 'T' at the end.