So I'm bi and always have been a verse with women and a dom with men, but after T, I've been more keen on the idea of bottoming for men. It didn't appeal to me pre-T, so I'm wondering if it's normal or at least someone else has experienced a change in preferences like this.

Not with preferences in sex but in the sexuality department; yeah. I think once on HRT you're able to think a lot clearer due to the lessened dysphoria and increased self esteem/confidence so your sexuality doesn't change; you simply realise the full picture of what your sexuality is. I don't see why it wouldn't be the same for preferences. Maybe before hormones bottoming felt too emasculating for you. Just something to think about.

I wouldn't say my preferences have changed but they've maybe softened a little.
Before I transitioned, I would get pissed if a guy showed any ounce of interest in me. I've never been with a dude in any way (not even kissing) and I just remember absolutely seething with rage when a guy would tell me I was hot/attractive.
Now? I pretty much don't care any more now that I 'pass'. I've have had a couple guys show interest in me at the gym and I'm like, "Awesome".
There's still no sexual interest in males for me at all but I'm enjoying the indifference to be honest. It's a lot less stressful. I'd imagine a good deal of it has to do with me just flat out being more comfortable in my body and how others perceive me.

Different sexual feelings occur frequently, though. HRT won't alter your sexuality so much as open you up to things you may have been actively repressing.
It's nothing to be worried over or embarrassed about and it's very common.

I think my preferences became clearer on T, but I wouldn't say they changed.

Early days on T yet but I did notice something - I'm bisexual, and since T I've had little to no interest in sex since. I'm not a very sexed person as is, but since T... just can't be bothered even thinking about it. I honestly expected the opposite.

I've only been on T for a month so I can't really say what is going to happen to me eventually, but my sex drive has definitely increased dramatically to the point where I am almost desperate to get off once I get started. Since the stakes somehow seem higher if I don't get off, I guess I am more willing to go to any lengths to make it happen. I can see how that would make me more open to experimentation or doing stuff I wouldn't have been comfortable with before if it meant I was able to have an orgasm/a better one. I think maybe before T we tend to have a take it or leave it attitude towards sex and on T we're more willing to work for it you know...Do some weird stuff...

And before T, I think dysphoria would often overshadow my need for sex and now, especially since T has made me less dysphoric, my sexual desire almost always cancels out my dysphoria. I think certainly if I passed I would be willing to do certain things I would have considered emasculating before. I'm not into dudes and hopefully it stays that way though haha. Not that there is anything wrong with LIKING dudes, just that I am not prepared mentally for a sexual orientation shift.

Now that I think about it, I think as of now T has increased my attraction to women and not done much to my attraction to men. I think there's always been a smidge of admiration there, and not just jealousy, but so far it hasn't gone beyond that since starting T. And really, my attraction towards women has been almost entirely directed at my girlfriend since she is always around and usually willing. I haven't like been drooling over every woman I see. It would be interesting to see how I felt if I didn't have a steady sexual partner though.

Ok, so I said I didn't have much interest in sex. The T seems to have kicked in. And I'm not sure if I'm just thinking about it a lot more now because I hated it much more before, and now I feel less inhibited... or whether it's just a straightforward libido boost.

It's really hard to tell.

As a kid I knew what masturbation was at about age 6-7. I knew if you did A + B then C happened and so on, just as a mechanical process, without the interest in sex per se. Just the feeling/sensation and knowledge of what that part of the body does if you mess with it.

As I grew up I think I had a fairly high interest in sex but a very low interest in actually doing it - 100% sure this was because trans. It's one thing to be sexually excited and to want to be sexually excited, and quite another to have to go out and play a role to have it happen to you with another person, or use that body you really don't like to achieve it.

At this point it's occurring to me more to think about getting off, but I still don't really want to. But I am less inhibited about getting off by myself, that's certain.   

Still really not keen on engaging with another person in order to get off.

So I guess my preferences and practices haven't changed a lot. It's just popping up as a thought far more often. I'm still more visually attracted to women, but still not interested in getting with one.