Can you update the "did not answer" flow to, instead of six busy signals and hanging up, be the dialog to end of the Matrix (1999)? The film concludes with Neo talking into a phone booth phone to the audience and I think it would be fitting here as an Easter egg.
Yes, that wouldn't be hard with the normal voip.ms call routing.
But my intent was for it to be as visually and functionally identical as possible to a phone booth you would've found on a street corner a few decades ago, just in an unusual place (and free). I've avoided anything in the normal usage of it that would deviate from that.
You could make it 99% of the time a normal phone booth and 1% you get the Matrix easter egg, that would be even more fun.