Heh, I have written/drawn some genderswap fanfic/fanart before and funnily enough that is the context in which I understand what you're saying. The essential characteristics of a character, or god, can be placed in a different social category by changing their gender... As someone who is officially female but actually agender, I understand gender better as a social category than a deep-set identity, though I know it is that for some other people, but that social category packs a punch, and it changes both perceptions and expectations. So changing the gender of a god changes their context. Like you said.

(The Furies as male, for example, would make me think of blood vengeance on a more national, almost political scale. Hephaestus as female suddenly aligns with things I associate with Brighid.)

I kinda do wander if there was some division of labour reflected in which gender a Finnish spirit was assigned when addressed? Like, this is the same deity, but I'mma gonna call them "veden emo" when hunting for pearls and "Ahti" when I want fish. I don't think we can really know.

Ugh, I should probably go looking for gay myth. Or we just make more...