I am running a large multisite network with thousands of users and subsite on it and I am using the support system plugin to communicate with my subsite admins.
When I want to display the history view of the single ticket manage page, the page takes almost 30 seconds (!!) to appears (this display time has continuously grown since the beginning of the network with the increasing number of sites and users on it).
If I look into the plugin code, it seems you are using the get_ticket_details( $tid ) function (in /incsub-support/model/model.php line 680) to prepare items for the page.
But this function is *very* heavy with 7 left joins returning a lot of information that are not used by the final rendered table .
Don't you think it would be possible to lighten the query a bit, in order to just return the useful information in an acceptable time ?