Well, we could look at the sales of Dragon Age, which has both straight and gay romance options. I very much doubt it had any impact on the sales whatsoever.
Your probably right, maybe its time to throw it into the game - full force and see what happens. Thats a risk (if it is a risk) that Sawyer would ultimately have to make, and one that the corporate folks above him may stomp-out for the reasons I have stated above - but maybe not.
I like the idea of having it added as Options, so that I don't have to Watch it or Experience it - that would be taking it too far if forced upon the player, I'm sure that would cause issues. But if it was optional, letting the player select what kind of experience they want to "deal" with, I would have no problems whatsoever if it was as prominent as heterosixual stuff.
Not that any of it is necessary, but the fade-to-black is a nice compromise for the games I think.