You said that CVC21202's "right right" rule prevented double riding, so it seems logical that if CVC21202's rule doesn't apply, e.g., in the situations I've described, then double riding would be permitted. In other words, if CVC21202's rule doesn't apply, I am entitled to take the whole lane. If I am taking the whole lane, cars need to change lanes to pass me, so why can't two cyclists share the same lane? I haven't seem any argument for that conclusion (and CVC21202 doesn't support you as you've noted), but if there is another section of the CVC that prohibits this, please do let me know!