You're still expected to be sexually available to trans people no matter what you call yourself.

I think labels should describe behaviours, not the other way around.

Afterall if getting attracted to people with mixed sexual characteristics isn't instinctive to everybody, that must mean something.

I understand your logic and you are kinda right, but my experience tells me something is still off. There are many men who are attracted to women and transwomen but can't get aroused to "complete" men. In the same way there are many men who are attracted to women only, so it's not that obvious to overlook a dick like you would do with a birthmark.

I myself, when I see a trans person I instinctively like one half or the other half but can't like them both at the same time in the same person. It's odd, it's like there's a switch in me: I like chips and chocolate cake but don't like chips in my cake, whereas others can.

And in those days where these thoughts weren't removed, many other bisexuals used to describe the same feelings.