This 4 hours thing you guys are talking about is wrong. There are multiple things going on that should make it so the public IP stays up to date.
Every few hours (maybe 4?) we may reannounce to Roon cloud services where your public IP is. This is probably what the guys saying “4 hours” are seeing.
If your public IP changes, that’ll break connections outbound. At that point, the Roon Core will make another connection back to our cloud services, thus updating the public IP.
If we know your Core has been around recently, but things are still not working from ARC to your Core, the our services can send “push notifications” to your Core. We use this normally to send metadata updates, get logs, and send alerts, etc… This push request tells the Core to tell the cloud services to refresh the public IP state, at which point the ARC will try again with updated data.
Have you run into an actual issue or is this just preparation for the future?