Yes, most of those plugins were made after this test was created. This one just sets "media.peerconnection.enabled" to false in Firefox's settings. However, it means you have to disable WebRTC entirely, not just the STUN requests.

Unfortunately, Chrome doesn't let you disable WebRTC at all unless you recompile with "-Denable_webrtc=0", and Chrome blocking plugins are easily bypassed (see some pull requests in my repo).