Substitution for "Named Destinations"

I'm using Named Destinations via Java Script and this works quite well. The disadvantage is the additional filesize (about 1kB) for every Named Destination (my PDF file has some 500+ of it). I'm looking for a possibility which yields the same result but without storing the relevant Informations permanently in the PDF file. Based on the position (x,y) and zoom factor the functionality should work from within Java Script.