There’s plenty of bisexual use of women in the many different freeuse worlds I write. Though I mostly hint at it, because my audience is what it is.
http://masterlovehurts.tumblr.com/post/156549489733/sydneys-summer-job-was-pretty-normal-she-spent
I also have some transgender posts: http://masterlovehurts.tumblr.com/tagged/transgender
I suppose a lot of “less dominate gay men” might choose to become “legally women” to have the advantages and responsibilities thereof.
You can also check out the subreddit for GayFreeUse if that interests you: https://www.reddit.com/r/GayFreeUse/