not really gay. not really gay unless it's straight up dude on dude. i used to think it was until i heard one argument from a trans girl that i was unable to argue. she said that chromosomes don't affect attraction-an argument that's really unwinnable if you factor in trans males or a cis person of the opposite sex that you just don't find attractive. though, a counter argument could be made for a trans person who has yet to take hormones or such.
But for purposes of creating porn, you wanna be clear on what to expect. And to write what you know. Speculating on what a man's feeling when he takes a dick in the ass is gonna come across phony and inauthentic if it's not coming from someone with insight. Does not really matter who that dick is attached to if it's coming from someone uninterested or just doesn't have the knowledge on the subject.
Incest and ntr get patreon support but you can tell which authors are faking interest. They're the ones who find excuses to delay that content while throwing as many side girls at you as possible. Until they abandon the game. Nobody wins because nobody is satisfied. You really don't want an uninterested author, you want them focused on what they know and like best.
I've only heard this second hand but a lot of Japanese futa porn is by LGBT authors and it's very helpful to young folks who are still figuring themselves out. It's more of a transitional thing over there, so it's not really written like futas are representations of what actual trans people are like. This author is doing something similar, the MC is pretty clearly a lesbian and using the dick spell as a tool.