Sounds like hiding IP is going to be opt-in? I'm not sure what the implications are of TURN but what would be the downside of making IP-hiding the default?
For instance, two users on the same LAN calling each other would end up bounced via the UK, which is a bit unfortunate if they are in Australia.
The solution is really to switch to using SFUs everywhere, which then solves both firewall traversal, scalability and privacy (assuming you’re happy for your SFU to know your IP - but if you’re happy for your TURN to know it, then it’s probably fine).