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. Precise vs non-precise self-identifications may mix with each-other: a chronologically 50 year old may identify as a 30 year old adolescent, for example. What that means is work in progress, but prima facie it seems to me that non-precise age may have parallels with transgender genders in terms of focusing on aesthetics and/or behaviors, e.g. in transageist worldviews, "adolescent", when understood as a self-identifier, may focus on having an adolescent aesthetics, interests and/or behaviors.
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)!
Transracialist "races":
Category 1: "races" based on ancestry: two sub-categories, orthodox and unorthodox. Orthodox races are those generally recognized, e.g. in the context of the USA, those are usually just "white", "black", "asian" and "native american". There is also "Latino" apparently but I don't understand what it is, and it seems like it's a different thing from the USA "races", so I won't include it in the list before understanding what it is. The unorthodox races are those that are not generally recognized, but they must refer to existing people e.g. it does not include blue-skinned people that can fire lasers from their eyes, as those people do not exist outside of fiction. Unorthodox races may be, for example, "blight" people ("white" and/or "black" people, or a mix), Americoceanians (native americans and/or australian aborigines, or a mix of the two), "Afro-Eurasians" (people from Africa, Europe or Asia, or a mix... it excludes native americans or australian aborigens), "West-Afro-Eurasians", that is, people from Western Europe, Western Africa or West Asia, or a mix... it excludes people from Eastern Europe, Eastern Africa or Eastern Asia e.g. someone who has a Norwegian father and Senegalese mother, or someone who has both Norwegian parents, or both Senegalese parents etc. is considered a West-Afro-Eurasian, whereas someone who has a Norwegian father and Kenyan mother is considered "mixed race", therefore not a West-Afro-Eurasia (as Kenya is in Eastern Africa)... someone who has a Polish father and Senegalese mother is also mixed, and someone who has a Polish father and Kenyan mother is NOT West-Afro-Eurasian, but East-Afro-Eurasian. Well, you get the point, any "unorthodox" categorization that is however possible to use and refers to real people is what I call "unorthodox race". You can get very creative with these, e.g. Southern-Chloe (yeah, I gave it a random name): those who are from Southern Germany (EXCEPT Bavaria) and/or Northern India, or a mix of both. The point is, "race" is a social construct and potentially it can be defined as anything and can and does change with time e.g. Irish and Italian people were not considered "white" in the early USA (most likely because Irish and Italian people were majority Catholic rather than Protestant), but became (categorized as) "white" with time. Many eastern Asians have white skin, and the reason why they were not (and still are not) categorized as "white" in the USA is simply because of racism, and nothing more. With "unorthodox race" you can conceptualize "race" as anything you want, and of course, this also applies to self-identification. For instance, someone from New Delhi may want to identify as "Southern Chloe" , which includes Southern Germans (EXCEPT Bavarians!) and Northern Indians. With transracialism, that can be done. Btw, Afro-Eurasia is an actual continent, as there are no natural masses of water that separate the landmass (the Suez canal is artificial, and does not count geologically!)
Category 2: "races" NOT based on ancestry. In some transracial ideologies, this is called "culture" instead. Example of category 2 races/cultures:
Note: as "cultures/races" (related to category 1 "races") usually have associated countries (e.g. Japan -> Japanese culture etc.), these "cultures/races" of Category 2 may also be thought of having associated countries. It's what I call "pseudo-countries", that is, fictional, idealized countries dominated by a specific culture e.g. Emo -> Emoland(?).
Types of transracialism:
Possible concept that I may explore in the future: physical vs metaphysical ancestry. Physical ancestry is where your physical ancestors were from, and that determines your physical appearance, whereas metaphysical ancestry is where (within the realm of ideas or even the physical world) your metaphysical ancestors were from, and that determines your behavior, personality, interests, opinions, religion etc. E.g. if you're emo, that most likely means that your metaphysical ancestors were from Emoland, and so on. When it comes to orthodox to orthodox transracialism (e.g. "white" to "black", or viceversa, etc.), that means your physical ancestors determine your physical look, and your metaphysical ancestors determine the "race" you identify as. Since metaphysical ancestors can originate from a physical land (e.g. Europe, Subsaharan Africa etc.) or a metaphysical land (e.g. Emoland, Otakuland etc.), your metaphysical "race" may be a race of category 1 or 2.