RE:timeisrestored - I'm really excited that this read is getting more traction! it sure can be difficult to convince someone of without having them read a novel's worth of posts though, haha. I've tried more recently to boil down the key points into just a couple of irrefutable facts which anyone who's read the comic will at least be able to recognise and, if they're open minded, hopefully think a little bit about:

A) Even if(!) cherub "sex" and "blood colour" are separate, the fact that cherubs can only mate in hetero-chromic pairs clearly compares blood colour and sex to each other;

B) Porrim makes it plain in no uncertain terms that blood colour and gender are linked in more ways than just the previously-established (between jade and femininity).

After this you just gotta ask this person to imagine and then describe the two symbols they most strongly associate with the two conventional genders and if they say anything other than 'a pair of astrological symbols' or 'a pair of colours' or both then they're either lying or they're too woke to be needing to have this conversation.

The bit about Caliborn sexing his leprechauns is a powerful corollary, but beyond a certain point it just helps for the reader to have, like, a very basic class-based understanding of gender? If you can understand that class is fake and that gender is a form of social class and also fake then it's such a short and doable jump toward figuring out the specific similarities in how blood caste is fake. I think one thing that makes this train of thought difficult for a lot of readers to hop aboard is that they are already quite familiar and therefore comfortable with the interpretation of caste as an analogy for race, and as such get it into their heads that it's ignorant or inappropriate to compare race and gender in such a way...? But, like, race is fake too! At the end of the day all of these things are classes arbitrarily assigned to people against their will. It's not such a wild idea that blood caste could be equivalent to more than one of these concept at a time!

Anyway, your understanding of all the key points in solid! There's just one thing I'd like to reiterate and put emphasis on: the binary-gendering of the trolls isn't quite "separately to" the duodecimal(?)-gendering of the castes. From a strictly literalist, worldbuilding-oriented perspective, maybe it makes the most sense to think of them as if they are, but to appreciate Homestuck holistically and as a symbolic text it's important to see the ways the two things are intertwined, as demonstrated in the above points. For these purposes I'd almost go as far as saying it's best to view trolls' binary gender as, like, a literary device that exists for the convenience of the human reader?* Which isn't to say that, for instance, Sollux or Tavros are strictly women on the basis of their low blood - just that we should be open to interpreting "lowblood things" (e.g. servitude, emotional availability via psychic powers) with a feminine tint and "highblood things" (e.g. obsession with feats of strength, dominance) with a masculine one. Even though not all highbloods are "men", as we understand it from our human perspective, we can understand that the role of any highblood in society is coded, so to speak, as patriarchal, and inversely for their warmer counterparts. It's this way of looking at things that is central to my understanding of quadrants as I've discussed it throughout the rest of this thread: when I call moirallegience intrinsically hetero-romantic, it's not that I'm saying all or even MOST moirallegiences consist of a "female" troll pacifying a "male"; what I am saying is that the nature of the quadrant skews towards lowbloods pacifying highbloods, which is coded as the same thing - EXACTLY like how cherub romance is presented to us as both hetero-sexual and hetero-chromic.

*And in a roundabout, metatextual way, this is exactly the case: Caliborn binary-genders the trolls for his own convenience, because as a cherub (a kind of audience surrogate) he would have trouble understanding the social dynamics of a culture with 10+ genders.