I noticed myself that recently I started to somewhat prefer (trans) women with penises. Not to a degree where I cannot get off to women with vaginas, and in fact I still like both kind of genitalia, and otherwise personality and other stuff is still way more important for me in a relationship (or would be if it wasn’t so unreachable for me at the moment). I also have an “unhealthy” obsession with anal sex, on both ends, but since almost everyone has a butt and I mostly use toys, I don’t really see the lack of a penis a great disadvantage on that front (also I’m a bit of a size queen myself), and also know from many of my trans friends that most trans women don’t really like to be the penetrating one.
Being a chaser, as far as I understand, is objectifying. Treating a trans woman as a womans body with a penis and not a woman who happens to have a penis. It’s about caring more about their genitals and body than them being a person.
Just like in the world of hooking up, the line between objectifying and just being direct about the reason you are there can be confusing.
If you respect trans women as women and not as a body type then I think you are okay. If you think of trans women as only applicable for sex, then you are not okay.