Arguments for transgenderism almost perfectly coincide with those that can be used for transracialism, transageism and other trans identities. Not exactly identical but there are interesting parallels. Work in progress, coming soon...
First draft. Potential distinction between "race" and "culture", as analogues of "sex" and "gender" for transgender worldview. Race is more, "biological" (for a lack of a better term), and "culture" is more psychological, self-identifying. For transageism: potential distinction between "chronological age" vs "self-identified age" (awful provisory term, I'll have to find something better lol). For age-related identities, one can make a distinction between "precise" vs "non-precise". Non-precise: baby, toddler, child, young adult, middle aged, senior etc. precise: 20 year old etc. "Teenager" can be ambiguous in English since when taken literally, it describes people from 13 through 19 (-teen numbers), but "adolescent" can be used as a synonym and it would be classified as "non-precise". Work in progress for philosophical implications of transracial and transageist identities.
Tentative description of transracialism: in certain countries, including (but not limited to) USA, Canada, UK etc. people are assigned a "race" at birth (without the consent of the newborn baby), depending on traits such as physical characteristics and ancestry. Potential example (to analyze eventually): someone (let's call him Dave, to avoid confusion as to whom the pronouns refer to) born in the UK who has been assigned the "race" "black" at birth, has been adopted by Chinese immigrants (who also live in the UK), and always lived in the UK, and of course speaks with a British accent, but can also speak Chinese and, within his adoptive family, adopts some Chinese cultural practices. On top of all that, Dave is a retro gamer and very strongly identifies with the retro gaming culture: his identification with the retro gaming culture, for him, is far stronger than any other characteristics he's been assigned by the government or society. It'd be interesting to analyze the identity of Dave according to transracial worldviews. According to some transracial view (which I may formulate eventually), "retro gamer", "emo", "metalhead", "otaku" etc. are also "races" (or "cultures" in other transracial views... the terminology may vary depending on the view). There will be a whole lot of different worldviews, as usual (this is the point of the philosophy section of this website, after all, lmao)!