Setting the font size works perfectly for input elements, but not for select elements for me. For select tags, I need to actively disable viewport zoom when the user starts interacting with the select element, and then reenable it on finish.
//the mousedown event seems to be the one that does the trick, versus 'focus', because focus fires after the zoom already happens.
$('select').mousedown(function(){
$('meta[name=viewport]').remove();
$('head').append('');
})
$('select').focusout(function(){
$('meta[name=viewport]').remove();
$('head').append('' );
})