Chronological View as it is currently designed is broken
Discussion board etiquette dictates that whenever you make a reply to someone and your post won't directly appear below you quote them so somebody else is able to follow what you are talking about. Having two separate view modes breaks this. While posts made by someone in chronological mode will appear to follow this convention to someone browsing in threaded mode, that does not hold true the other way. Fortunately fixing this is relatively simple: when in chronological mode make it so that the parent is automatically quoted at the top of the post but keep it hidden by default so as to not clutter the page.