Eh, maybe it is just me, but like, besides Vahn (who I do think would look good in a skirt), I do not think the rest are far off to what most people would consider femboys. Liamme, Del (who game specifically calls that), Yoma (his unused bust makes it more apperent)...
But lets move from TiTS and stick to the realms of CoC2.
The ones that people consider femboys are: June, Jin-Jin (I think?), prince Nyze, Nikol, Elf Boy, Boomer, Mallach, Vicky, Sugo and, of course, Berwyn (who Wiki does not even put under masculine category).
And, generally, I can see where people are coming from when talking about these guys. But under my umbrella, some other guys could also fall under that category.
Quinn, Elyon, Darius, Taka, Whisper and Nakano. Like, what is the upper limit where we go from femboy to pretty boy/twink? I think this basically a me problem but I do get bothered somewhat by it, especially when it comes communicating with people. When someone tells me that they want more musceline and/or feminine guys I struggle to understand what they want exactly. Since, to me, basically anything under Brint/Younzan (hunks) is someone I consider on more on feminine side of things. How much or less is one feminine than other? Not really something I bother to put a scale on.
Edit: For example, what do you consider femboys and what do you not? In that thread, you argued that both Dell and Kase are not ones. Why? Especially Kase since the game seems think otherwise. I am not saying that that makes your opinion wrong. It is just me showcasing that you and I (and basically every being on this god forsaken/devil blessed) earth seem to have different connotation for what constitutes as a femboy.