When playing on MCCI w/ the mod, MCCI Sound Effects don't work (background music does though!). Also, sound randomly dies after a couple of minutes of playing and the issue doesn't get fixed until the sound device gets changed.
Here's a video of the issue happening and me fixing it:
https://www.youtube.com/watch?v=jhkBSFJrp9Y
While this is extremely weird and I haven't seen on any other server, I don't believe the server is using any of the exploits that the mod prevents.