A lot of webservers have protective configurations to prevent them from being overloaded. When a crawling tool gets 503s, it's often a sign that either the rate of the crawl is too fast, or the number of simultaneous connections is too high. Check the tool for these settings and if they are...
Having even a simple count per day of the registrations made by the Add-on would be a good proof that this is really helping to get new member joins. If people can show many registration from this, more forums will want to use it.
There's another version dependency that limits this currently to XF 1.4.
In: ./QuickReplyGuest/Model/GuestQueue.php - you use the field: xf_forum.moderate_replies
However, that is only in XF 1.4. In 1.3, that field was named "moderate_messages". The 1.4 upgrade renamed the field.
It involves multiple tables to fully control read/unread state and position.
Read or unread state is a flag, 'is_unread' (0 or 1), in the 'xf_conversation_user' table. But, the position of where in the conversion the member has read to is stored as a timestamp, 'last_read_date' field, in the...
Well, in this particular case, it's actually true that sites not using SSL were better off.
The entry point into shared memory in this case was directly tied to running an exploitable version of openssl. Any site running the versions effected, could easily be entered into and have their memory...