You don't have to put so much effort into not offending anyone. It's fine to say "that's not British English, by the way". Half of your post is dedicated to not

You don't have to put so much effort into not offending anyone. It's fine to say "that's not British English, by the way". Half of your post is dedicated to not offending delicate Americans by reassuring them that they're not wrong. I'm sure they know.