It seems that there are a number of us that have the same worries!
I'll tell you my current decision, in case it helps anyone else struggling with this. I decided to make my main genre "Drama" instead, LGBTQ+ second, and Romance third. I also added an lgbtq tag, a romance tag and a mythology tag. I haven't used tags before, but one look at the collection of tags in the main page paints a very vivid picture of the story I'm going to tell, which is perfect for me.
I came to this conclusion by thinking as the reader. Like I said, when I click the Romance tag, there is heavy expectations of a particular format. There's a Female Lead. There's a Male lead. They fall in love. I'd like to think this is what people clicking a genre would expect. There is heavy romance elements in my comic, but it will not follow the Romance tag expectation, so taking it off as main genre seems like the right choice.
I put LGBTQ+ as the second tag, and since my first tag is NOT Romance, they can expect LGBTQ content, but not particularly romantic. This is exactly the vibe I'm looking for.
With this conclusion, I think my problem is solved. I'll give my thoughts to people who want to discuss further ie. having trouble with the LGBTQ content genre/tag.
Edit: I changed the Romance genre to Horror. But put a note in the summary that it will have Romance elements. It's too bad since I think "Supernatural" would fit my story better than "Horror", but there will be some dark stuff somewhere along the lines, and completely taking out the Romance from the main genres looks right, so there will be no expectations.
@ghostoast No worries! I really didn't judge your opinion. I thought you were thinking along the lines of "people looking for the LGBT tag will prefer more LGBT content therefore, better use the tag sparingly" which is totally understandable. That was my worry too.