I have no idea but I am incredibly interested in this. If they want to go the easy route they may have it be that we don't see our patron directly, they just communicate through some sort of distant but thematic method so that we're free to headcanon them as much as we like. I think that's the safer option and I wouldn't be against that. My first character will have an archfey patron and I headcanon it as being some kind of warrior fey that taught her to use a blade. So perhaps they'll have our patrons communicate to us in our mind, with the narrator narrating their thoughts and desires and responses to us.