iPad landscape zoom

It seems that "out of the box" Zen has an issue (or rather iOS has an issue which manifests in Zen) that in landscape orientation, iPad (and i suppose iPhone too) zooms the viewport and doesn't respect the native resolution, and therefore any breakpoints designed to display content differently for iPad in landscape orientation.

I can fix this (per #1615526: Initial scale, type on iPad and the javascript used in Susy) with:

if (navigator.userAgent.match(/iPhone/i)||navigator.userAgent.match(/iPad/i)) {
  var viewportmeta=document.querySelectorAll('meta[name="viewport"]')[0];
  viewportmeta&&(viewportmeta.content="width=device-width, minimum-scale=1.0, maximum-scale=1.0",
  document.body.addEventListener("gesturestart",function() {
    viewportmeta.content="width=device-width, minimum-scale=0.25, maximum-scale=1.6"},!1))
  };

I can't seem to find any other issues like this with a confirmed resolution. Is this the preferred solution or is there some better way?