But at NEFFA they read “man in a dress” and behave according to those gender expectations. Short of adopting a hyper-gendered presentation (hard to maintain over a day of festival dancing, as it would involve heavy makeup and foundation garments) I can't figure out what I could possibly do to counter that misreading. I suppose I could try F-cup breastforms but I'd have to buy a bunch of new clothes (most of my wardrobe would be too tight on top) and it's not who I want to be anyway.

No, I don't think you want to up the amplitude. I think you want to refine the resolution. One doesn't make oneself read as more feminine by exaggerating a few physical characteristics, but by making one's presentation more thorough and detailed.

Do you have anyone helping you with this?