Can content for Pallet 1 or 2 be positioned at the bottom of the page?
Maybe with some positioning css or moving entire sections with javascript? But that could change their behavior on mobile devices. So be sure to use a media query if using css.
But you could use the phplugins main_bottom (pangolin) or footer_top or footer_bottom (pangolin and kookaburra) hooks to insert content. That would leave the pallets to behave as they normally would.