I think the film is brilliant, and it can be read as LGBTQ+. The protagonist uses drag to collect information about the girls who were sent to the Prince. She dresses as a man, and that's why she can enter the 'Boys Club' literally and figuratively in a poor district of Budapest. Also, in the last scene, we see Írisz in a WWI trench, and I think that Írisz also uses drag to participate in the boys' game, namely war.
The style of the movie can be a little confusing, but the viewer can put the pieces together, and it does not require hard work, just paying attention to - not even tiny - details. I think the style and the narration of the film open the door to many interpretations, including this LBGTQ+ one.