I can't even see the point in "fitting in", because those who care about how you express yourself aren't going to accept you as transgender anyway, and the people who are going to accept you aren't going to care if your expression matches the stereotypes they're used to.

This is so important to understand, innerstand, overstand and outerstand.

And that's what gender critical means.

I don't think there is such a thing as "transgenderism", as it is not an ideology. It is a human trait, such as this person is transgender, or that one is cisgender.

There is another issue I take with this approach. You seem to think that transgender people (in the positional sense you employ above) acquire the societal customs surrounding the sexes (like skirts and make-up or ways of talking and walking) and equate it with "being that sex".

This is not accurate though. There have been studies who show that trans people are no more stereotypical feminine or masculine than their cisgender peers. Cis people are all over the place with respect to gendered societal norms, and the same is true for trans people. (And of course non-binary trans people challenge the norms even further.)

To better understand what gender identity is, consider the horrific assignment of gender performed on intersex people. When infants have ambiguous sex organs, a doctor decides, often on his own visual inspection about the future ability of the organ to penetrate, whether to mold it into a penis or a vagina, and not even tells the parents, so they think they've got a cis boy or girl the whole time. Over the years it has turned out that these people feel uneasy and when seek answers they discover they should have been another gender all along. So it is something in their brain that tells them "I am not the correct gender". The same thing happens to transgender people. This is what it makes a protected trait.

Also, the provided definition of "acquiring the societal custom of the opposite sex thus becoming the other sex" does not account for dysphoria, a feeling of unease to the primary reproductive organs or secondary sex features (like body hair, breasts, muscular structure and the like). And it is very shallow from a sociological perspective as to how deeply ingrained are these customs to the identities of cis and trans people alike.

The starting point here is usually to notice how asking about a baby's gender is the first question asked, and everything is shaped from there (baby room coloring and selection of toys, the content of compliments, and conditioning their plans for the future).

People never complain about cis women "always" being such stereotypical dolls and cis men being such insufferable chuds. They only complain for specific trans people that are performing at the extremes, and the only reason is that people don't see trans people's gender are equally genuine.

This article may have some direct relevance to you: https://medium.com/@viridiangrail/so-you-found-out-youre-agender-because-you-don-t-understand-trans-people-886fdee6f178

I personally smell either some kompromat-style blackmailing situation (remember him defending trans people in the past, as well as having a much lighter stance on being "culturally christian"), or money in behind the scenes.