"Interestingly, it's become harder to talk about that in the last couple decades, because there's been a trend to insist that gay men are just like other men except for the tiny wee detail of sexual attraction."

As you go on to say later in your comment, that is the price of assimilation and aspiring toward respectability! I can't fully imagine what it was like during eras I wasn't alive for, but I do sometimes get the sense that there was a more defiant, rebellious recognition of all queer people as the "other" that is gone now for the gay guys with corporate jobs and marriages that look closed & tame and conforming to the outside world. The pressure to buff off all one's edges is strong.

I used to be surprised when I'd befriend a queer man and find out that despite how out he was in the scene and how effete and queeny he was around me, he wasn't out at work, and zipped all those mannerisms up whenever he interfaced with straight society. Since my difference transness was (at the time) so unavoidably visible, I presumed that gay cis men who could mix and mingle alongside the rest of society must have had it less "hard." After enough conversations where our anxieties rhymed with one another's exactly, I realized how much that wasn't the case.

And yes, we do need more research & writing into how gay men experience and conceive of gender! Many feminist scholars have written about how "butch" or even "lesbian" are themselves gender-transgressive categories, and there are so many nonbinary people who identify with those labels but do not identify as women. There is comparatively little discussion about gay men who experience their gayness as a core part of their gender -- but it so obviously is for so many people!