I'm a 39 years old bisexual french guy working as art director in the France west coast. Here under is an extract of an article published on "Tetu magazine" in 2018 about gay porn art production.

- INFORMATION FOR GAY PORN ARTISTS :
In may 2017, a library in "le marais" (the famous Paris gay district) in collaboration with the great artist Gengoroh Tagame launched a survey about this subject through a printed (and anonymous) form available in the essential well known "gay places" of the city like "Cox Bar", "Bears den", "Les Maroniers", "Raid bar", Gibus", "Banana café" and many other ones in Paris.

The form (anonymous and freely available) was presenting a list of "themes / tags / words" associated to gay art porn, asking the respondant to order those groups in order of preference.

1790 forms have been returned filled with the global following result :

Muscles / sports / hunks
Police / military / firemen
Big dick / anal / blowjob
Horses / centaurs / donkeys
BDSM / control / roleplay
Gangbang / orgy / threesome
Fantasy / magic / mythology
Tentacles / aliens / insects
Monsters / creatures / undead
Robots / superheros / SF
Blood / violence / hardcore
Sims / avatars / winkies
Cartoon / sketching / comics
Dogs / wolves / foxes
Furry / yiffing / zooanthropy
Hentaï / yaoi / manga
Kawaii / cosplay / japanim
Twink / teen / skiny
Girly / sissy / futanari

(of course we can discuss about relevance or even bias for this nomenclature, but the result still is quite obvious - IMPORTANT this result is only relevant for the french population).

- ABOUT GAY PORN ART PRODUCTION :
Tag words used on the web, links, libraries references and several other available data or tools are usefull to make the current thematic distribution easily measurable.

Aproximativly 88% of the worldwide gay animations, 3D arts, paintings, drawings...are productions foccused on the hentaï, yaoi, furry, sissy, twink, manga and cartoon references / tag words (wich is olmost exactly the opposite of the french population survey result).

Due to the Japan hentaï and yaoi productions and culture, those tag words and references still are the most common (67%) all gay porn art productions data combined (for almost 30 years).

The furry tag word relative to gay porn art production has a progression of 11% from 2014 to 2017.

For the french gay population, artists like Average Neighbor, Joecalzon, Brein_3d, Homoeros (work samples available on patreon.com or other specialized websites) are the only producers taking care of their tastes (by strategy or natural art orientation).

- FRENCH GAY MEN :
...are sexually most attracted to manly men not into stuffed toys or obviously women. Most of the time, about 3D porn or comics porn, they just prefer consider straight oriented productions in wich it is far easyer to find high quality, realistic scenes and models, and even horse actions...

Thanks to artists like Animopron,
XXXKIN and some others.