Nope, there are little to no lesbian couples, in a bit of spoiler alert, there is a scene in the novel that has the MC pretty much learning the very DNA or rules of the universe she lives in, and yeeeep, it's a BL world alright with women getting the short stick even in gay couple terms.
Yes, what i wrote is true, she literally learns the truth of the universe and it's pretty much the synopsis, it's a BL world, don't even know if it counts as a spoiler when it's kinda part of the synopsis.