I'm agender and on T due to physical dysphoria. I don't consistently pass as a guy yet, and while I welcome the majority of the physical changes, I have to admit I'm not excited about being thrust into a completely different set of arbitrary gender expectations.
The thing is, I'm going to get misgendered regardless. I can't escape the fact that most people I encounter are going to assume I'm on one point of the binary or another. So I figure I might as well be comfortable in my own skin.
I tend to wear masculine clothing in bright colors because that's what has always felt "right" for me. I feel as dysphoric dressed like a super masculine guy as I do in a frilly dress. This means that, yes, I usually get read as a butch lesbian or a gay man, and I face the respective social consequences. Fortunately, I'm in a pretty liberal area where I'm a lot safer than I could be elsewhere, but I'm aware it only takes one transphobe to screw up your life.
For me, it's worth the risk. I was frequently suicidal before I transitioned, to the point where I truly believe my biggest threat is myself should I have to go back to that. Even just the effects of T on my brain chemistry, regardless of any physical changes, are a massive boost to my mental health. So while T isn't a universal positive for me--it almost never is for nonbinary people--I've never regretted it since I started. Second puberty isn't fun, but the hardest part really was working up the courage to start in the first place.