the name of the file is autoptimize_<md5($content)>.js (or .css). this implies that if the content is identical (to the comma), the name is the same and the cached file can be used. a file with a different name has a different hash meaning it must have something (a space, a comma, a digit, a newline, …) different in there.
don’t know if you did already, but if not you could force AO not to aggregate any inline CSS or JS (which in 99.9% of the use cases are the reason for cache-misses and hence cache size increases) by using the API;
add_filter('autoptimize_js_include_inline','gad81_ao_include_inline',10,1);
add_filter('autoptimize_css_include_inline','gad81_ao_include_inline',10,1);
function gad81_ao_include_inline() {
return false;
}
For AO 2.0 enabling/ disabling inline aggregation will become an option in the settings-screen (replacing the “look only in head”-options).
frank