Based on available information, 'Behind the Curtain: Stranger Things: The First Shadow' does not feature any identifiable LGBTQ+ characters or themes. The documentary focuses on the behind-the-scenes aspects of the stage production, with no reported LGBTQ+ content.

No information was found in available synopses, reviews, or production details for 'Behind the Curtain: Stranger Things: The First Shadow' that describes transsexual characters, transgender community portrayals, or themes of gender and sexual transformation. Therefore, there is no depiction of such elements within the film's narrative or behind-the-scenes focus.

The movie does not contain any action or adventure elements.

The film is a documentary about the production of a stage play, featuring real people involved in its creation rather than fictional narrative characters. Therefore, the concept of a 'gender swap' does not apply.

The film is a documentary about the making of a stage play. No information is available regarding the specific roles or ethnicities of the listed actors, nor any comparison to established characters from the Stranger Things canon. Therefore, a determination cannot be made.