You're fixated upon utility in a virtually post-scarcity society. The fact New Texas has contraceptive in the water supply but continue to fuck all the time should tell you how important having an economic niche is there. Also, why do you think faux-cows can't provide all the sexual functions regular bulls do? Why do you think they can't fill the liaison roles the cows predominantly have? Why, in your mind, are amazons not also figures of pity for not fitting into the dichotomy?
Really struggle with the idea they don't work, or somehow the fetish they serve doesn't fit upon a planet concerned with permanent over-sexualising TFs. Even if you think they have no stature on NT, does it matter even slightly? You write about the PC being trappified, you know what the punters generally want to hear.
More of a social niche and how they're going to make sense within the context of the Treatment - both within the setting of New Texas and the erotic content of the transformation. With the specific fetishes it evolved around (lactation, stud-as-dominant/bimbo-as-submissive, ridiculous muscled male physiques and ridiculous curvy feminine ones) the faux cow idea just doesn't fit in anywhere. I say amazons still fit it because the way the wires cross give them bullish traits as well as some of the cow ones; you've still got your lactation and it's obvious what male Treatment features they're getting. The end result is a bull physique with tits. Both physically and socially they still fit into the whole scheme of things even if they're a little odd. The faux cow on the other hand (as it's being vaguely envisioned) doesn't actually get any of the cow features, though: no breasts, no bimbofication, no ridiculous feminine proportions. Other than the wang they don't get any bull features, either. So in the context of the Treatment: what happened, exactly? That's important to know when writing the actual transformation scenes themselves since they all have an obvious erotic theme. The archetype doesn't really make a whole lot of sense within the context of what the Treatment is supposed to do.
When you throw them into the mix of New Texas it's not clear what they're supposed to be, either. All the girls fetishize big manly bulls and their silly ultradominant porn personalities and all the boys fetishize big squishy milk tank cows and their silly untrasubmissive airhead porn personalities. Amazons, especially if they end up with a D, can easily fill the role of the bull for girls (and boys, even) so even if they're nontraditional around there they still fit into the general preferences and social order. A faux cow doesn't tick off any of those boxes for either cows -or- bulls (who there likes them, then?) to the point where they feel like a completely foreign fetish and personality type around there.
And they p. much are, really. That archetype is more the sort of thing you'd find in a specifically amazon-themed society, one where the women really get off on seeing the men looking small and pretty (but still with big tackle boxes). Zephyr even touches on that a bit and the context that she brings it up in (fantasizing about a complete inversion of what they have now) just illustrates how out of place they are. If their theme is supposed to be emasculation how did the Treatment get wired for that when it's the opposite of what it's supposed to do and does that really fit in on New Texas, a place where very few people are likely to give them a genuinely humiliating hard time about it as opposed to a gentle ribbing and maybe pity?
It's much harder to write content or even come up with ideas for them when they clash so hard with the rest of it; it's like they got written out/into a corner as the Treatment and New Texas became more realized and now they're waiting on some justification for their presence and theme to their content, something that'll work in some actual bovine aspects and determine what they are exactly as a mix of bull and cow.