Hi! Really excited by your work! I'm working on a similar project built on NixOS and curious what you thing.
My goal is to have a small nearly zero-conf apple-device-like box that anyone can install by just plugging it into their modem then going through a web-based installation. It's still very nascent but I'm already running it at home. It is a hybrid router (think OPNSense/PFSense) + app server (nextcloud, synology, yunohost etc). All config is handled through a single Nix module. It automatically configures dynamic DNS, Letsencrypt TLS certs, and subdomains for each app. It's got built in ad blocking and headscale.
I'm working on SSO at the moment. I'll take a look at your work and maybe steal some ideas.
The project is currently self-hosted in my closet: