I personally think that LGBT genre is for stories that include one or more LGBT characters, even if the MC is LGBT, but is not necessarily romantic, could be a friendship o just a gay single superhero that saves the world, he maybe gets some crushes but never a relationship because he is a superhero and that create trust issues to meet new people (it's just an example, but if someone wants to use that idea, go ahead
)
BL is more focused on Boys Love, the MC and the Love interest, nothing else, the story is about them in any scenario, but at the end is the story about male x male romance, it can be sexual, it can be just innocent moments, it can be half of the comic the characters separated and the other half they as a couple. Just ignore the fear of BL being infamous because some toxic fans, did you know that some people are really trying hard to find a good BL story? and you could be that person! So don't be afraid to classified as BL if your story is about a male x male romance.