If you set up renditions (same Folio Name, different Size values) between folios, it should work. Try shaving off one pixel and creating a 1024x767 folio and source documents. It definitely won't show up on the iPad (iPads viewers display 4:3 aspect ratio folios only), and if you set up renditions properly, the 1024x768 folio won't show up on Android.
An update: I finally had a chance to test this. Took 1 pixel off the width of the original document, and it worked perfectly.