Definitely neat for a small personal or community site where you don't expect any kind of public traffic.
Not so useful for something that might end up on HN and go down.
Could also put a CDN infront to lighten the load on the upstream but guess what, now you're not just hosting on your phone anymore and might as well use other cloud services where often you can host more for free than a phone can handle
For those who need this I'd recommend Tailscale and their MagicDNS. You'll get access to this device for free from anywhere, with a working DNS generated for you, and only from devices that were allowed to.
Not so useful for something that might end up on HN and go down.
Could also put a CDN infront to lighten the load on the upstream but guess what, now you're not just hosting on your phone anymore and might as well use other cloud services where often you can host more for free than a phone can handle