I'm not sure what you mean by "pronoun cards," either.
You mean like a business card you hand out that says your pronouns on it, or a name tag sort thing you wear that has your pronouns on them?
I feel like it would out me, and I pass as a cis little boy.
I often like toying with people, like having half of them call me "she" and half call me "he," but get anxiety about the two different pronoun-callers crossing paths.
Idk... I feel like I do subtle ways of outing myself, instead of indirectly saying them, like writing an autobiography where I talk about myself in the 3rd person and use "they" pronouns the entire way. It makes people ask questions like, "Why were you calling yourself they?" Then I'm like, "Because it's my pronouns!"
I feel like I get slight dysphoria from being called "she" pronouns and feel mad/ afraid when I'm called "he," but at the same time like I don't feel like spending 20 minutes educating every person I meet who openly genders me, which would be quite a few people, like sales clerks, cashiers, etc. Not a lot of people I've met understand things ~beyond the binary~ and I don't have the time/energy to teach them all
For that reason I'd probably just keep living how I am/ not using pronoun cards