I'm ironing out some quirks at the moment (a vulnerability was found and I'm profiting off that I had to do some core modifs to do some refacts too), if you're interested you can sub to [email protected] I'll post an update when things get rolling.
If top level domains are user-configured based on which start zones users select, could that run into issues where two people think they're going to the same domain, but actually go to different domains?
It sounds like having your instance admin in charge of what google.com points to, instead of ICANN being in charge of all of them.