> I would think of using 'Frenchie' to refer to a person as being affectionate banter

Not sure about other English-speaking countries but I'm fairly sure we don't use that word in England. It's exclusively the dog. We usually call them a frog which is quite derogatory, or use a certain tone when saying e.g. "he's French" (implying "ugh"). We also don't call Canadians Canucks but certainly call USAians we dislike Yanks

We English don't really do affectionate banter with the French. We either like/admire them or hate them lol

I mostly admire them, for the record (but it can be testing at times – we find their arrogance quite annoying ;)