Hi,
I usually don't voice my opinion, but I will this time.
SDP munging is an anachronism. It should have been banned in WebRTC at least 5 years ago.
When it works, it is great, but when it doesn't it just doesn't. And there's no guarantee for it to work, or what even "should" work with SDP munging.
The fact that all browsers support it is only due to the fact that they all rely on a single implementation - libwebrtc.
The urgency that compelled the plan of this might have started due to a specific security threat, but the existence if this hack (I wouldn't call it a feature) is a potential for future security threats.
It is best if we as an industry resolve it sooner rather than later and give it the urgency it needs.
Yes. It is going to be a headache for implementations to make the changes needed.
But it is necessary for the health of the ecosystem of WebRTC.
Just my two cents.
Regards,
Tsahi