I think that depends on whether Congress is in session or out of session during the 10-day interval.
You could be right...I’d have to dust off an old law book to see if a pocket veto requires Congress to not be in session. Since they never go out of session any more, there would never be a chance to have one occur. I don’t recall ever reading about a law coming into effect because the President didn’t sign it in time, but maybe that’s how it works. I would have known when I took con law, but that was a long time ago.
You are right, Article I, Section 7.