For an online multiplayer browser game, real time games need UDP-like networing.
And it has to be server-authoritative(client's can't cheat)
So the TURN server will be able to verify the messages before relaying.
You must be a WebRTC expert with good knowledge about TURN, STUN and UDP(RTP)
Please describe your webritc experinece, and also about turn, stun on your proposal.