One last question on this subject: would caching of these specific AJAX requests (started through re_compare_panel) work?
I did a simple test on W3 Total Cache setting it to cache /wp-admin/admin-ajax.php, but to not cache wordpress admin user (so to be sure that only the AJAX requests from visitors would be cached, and that if I login as admin on my site I would not be cached).
But testing this configuration shows no improvement on load time of the AJAX request on any page. So I'm assuming it is either not possible to cache these requests or I don't know exactly how to configure W3TC to cache them (maybe only configurable through custom function)?
Any insight on this subject would be greatly appreciated.
Thank you in advance.