The issue I have is they removed the ability to use a custom domain and DNS. Happened sometime between 2019 and 2021. I have an old pdf I made showing the long removed options.
That kneecapped the service for a lot of people years back. Without a way to access it externally, playing with hardware was no use.
It wasn’t externally accessible after they removed the entire section from their gui.
Perhaps they added it back after people left. I tried again in 2021 and that wasn’t an option nor was internal IPs only after being able to do what you described previously.
But the point remains that they have changed their terms previously, and pray they don’t alter them any further.