Gender preference is hard to change. For example, I was gay before and liked dating guys. Gradually, I found myself as a real woman. Yes, I wanted to be a real woman, so I chose to be a trans girl. I still liked to date guys. At this time, I am straight. But no matter what, my identity will change; I love dating guys. Therefore, I say the preferred gender cannot be changed sometimes.
If someone is a crossdresser and he likes to date gay, it means that he can be gay. As he is gay, he wants to date men. Although he chooses to be a trans woman, he will also like guys.
I want to say that crossdressers are what people want. If someone wants to date people as a crossdresser, this is not wrong. But we should tell the person in advance. I also know some cross-dressing men on trans dating sites. This is not bad.