Yes, I have. IMHO, you can't understand the European Middle Ages without the "Roman Catholic Church" as an institution. So when I created a faux-Venetian Renaissance setting for a game in Fate (and now Cortex), I felt that I needed a similar institution in society to create the faux-Renaissance feel but one that also let my queer friends play queer characters.Now of course you don't have to explain it; a lot of people just want to have fun playing, and you don't want to annoy or offend players! But has anyone with a flair for worldbuilding tried to come up with reasons for all this as part of the history of your world? The deities set it that way at the start? (Probably the easiest way.) Feminist movement 500 years ago that's long since triumphed and nobody holds stereotypes anymore?
So I created the Angelic Church, which is a religious institution that venerates seven angels/spirits as the primary aspects of the will of the Creator. So religious ethics formed around the teachings of these seven virtues rather than those of any Abrahamic religion. This naturally would produce a diverging set of norms around things like gender, sexuality, etc. Homosexuality is not considered a sin; however, things like promiscuity, lust, and hedonism likely would violate socio-religious notions of the virtue of “temperance” regardless of sexuality. Moreover, homosexuality could potentially be perceived as "incovenient" when it comes to arranging marriage alliances with other families and/or producing heirs.