I've been using your nice extension since 2 years and already experienced some issues (some keywoards were causing infinite php loops and internal server errors). Unfortunately you couldn't solve the issue but I managed to remove/change the keywords causing the troubles case by case.
This worked fine till last week when I updated the site to joomla 3.5.1.
Then, like 50% of my website pages generated internal server errors :-(
Thanks to the server logs I could see that your extension was creating the problem and had to deactive it.
If you want I can communicate the server logs if you want to investigate a but further.
I'm using on the website the extension in version 1.3