@duncan: Yes, this helps clarify the documentation. Tx!
It only took me a few hours on two occasions to tease apart the subtlety here. First time, I ‘fixed’ the page length/footer relationship on 960px only to later discover it $%$#d up my 320px. Then, when fixing the 320, it re-arranged the 960… Almost tripped on it again today when moving a new text. And the relationship to Popup positioning… oh… my…
NOTE TO SELF: Do NOT deselect ‘Follow Footer’ when adjusting page length or it sets ALL ‘Follow Footer’-toggled items to the vertical position of the sample page when re-toggling Follow Footer.