It's possible to find someone, they do exist, but they're rare. and I say this given that I was a gay guy (am now a pan trans girl) that dated a pre-t trans dude (he started T about a month into the relationship). Like... that dude was a man, undeniably, because that's what he knew himself to be. I never once thought of him as anything else. There are absolutely people that will love you for you, you just gotta be patient, and careful
I am a trans guy and so is my boyfriend, we started dating around the time we started transitioning. and we have a friend who’s a trans girl and she dates trans guys, a few who have been pre-t. I also know a trans girl who’s with a cis guy. so it’s not like exclusively t4t, but in my experience those are the best relationships because they really get it.