Despite uploading the 'upgrade only' files multiple times, I do not get the option to upgrade my installation - only do a fresh install, which states it will remove all existing data because it detects my config.php file.
Intermittently, I get one of three errors on any page of my XF forum.
"An unexpected error has occurred" on white screen
Google Chrome error "Error 139 (net::ERR_TEMPORARILY_THROTTLED): Requests to the server have been temporarily throttled."
Mysqli statement execute error : Prepared statement...
I'm interested in this too. It may be worth referring to the Vanilla ProxyConnect plugin, which does exactly this for Vanilla Forums. May be able to copy the method, essentially.