"Whoa! What, exactly, is a "trans lifestyle" (I can't italicize "lifestyle" here, as you did)? Lifestyle indicates a choice; trans is not a choice. While we may have made the choice to live, openly, as trans women, we don't, necessarily, have the same lifestyles.
It could be argued that a cross dresser (included under the trans umbrella) who attends meet-ups with other cross dressers every Thursday night has adopted a lifestyle. Of course, I'm not saying that's a bad thing, and it certainly shouldn't define who that person is. It also is not something I, as a trans woman, choose to do as a lifestyle. Still, I can be an ally to a person who participates, without engaging in said lifestyle, myself.
I think that attaching a lifestyle to trans perpetuates a stereotype that those who are not allies like to use to define trans people. Here's an example, from my own life, just after I had come out in an email to some long-time "friends":
"> Thanks for your reply to our invitation for our 2013 Christmas Holiday Party.
> We are pleased that you have decided to live your lifestyle in all honesty to yourself. This must be bringing a contentment and joy that you have never felt or experienced before. And that's a good thing.
> That said, we feel our Christmas Party is not the best setting for your first appearance in our house in this new guise.
> We are your friends, and look forward to seeing you soon. Perhaps at your house or the Eagles. Here's to a happy and joyous holiday season."
As you might imagine, I was not happy to receive this email. But, it wasn't just because I had been uninvited to a yearly party that I had been welcomed at for years. Their use of the word, lifestyle, followed by the shoe-drop phrase, "That said," and the condescending tone, infuriated me. I still have my unsent response draft in my email archives, as well. It was nasty and unbecoming of the lady I try to be, however, and I did the right thing by not sending it. Ironically, their response was much more about their "lifestyle" than it was any they perceived mine to be. And, yes, I was invited to subsequent holiday parties, and I did attend. And, no, they are not my allies; they have really not changed much at all. I have only maintained a relationship with them in hopes that they may, one day, realize that I am not just living a "lifestyle." Oh, did I fail to mention that these people are Trump supporters? So much for my hopes, then."