i wrote a reverse proxy that you can run on a cheap VPS that with a domain name with the wildcard configured on the DNS service configuration, combined with a wireguard connection, allows you to expose your home relay to the internet:
https://github.com/mleku/realy/tree/dev/cmd/lerproxy
my relay is now working very nicely, has an automated access control that allows everyone in your follow list to read and write from the relay, you only need to put your npub hex into the configuration and publish your follow list to it and voila
still need to do a lot more work on all of these things but i think that people would pay for being able to run a relay on their computer that everyone in their friends list can automatically use (just need to make the deployment a bit simpler so it automatically fetches the follow list by scouring the open relays)
i think i will try to focus on making everything needed to do this... even, maybe bake this reverse proxy into the relay so you literally just DM the relay bot, set your subdomain username, and zap it and it sets up a wireguard client and on the client side the relay lets you drop that wireguard client config in and the relay automatically connects up to it and listens for stuff
a lot to do but i know all the pieces required, it's just some time to make it happen