Shameless plug: I wrote a DDNS service in Go [0] that uses Netlink on Linux and the IP Helper API on Windows to monitor network interface addresses in the most efficient way possible. As a result of working on this project, I sent 3 separate CLs to the x/sys module.
Yes, but this is actually a different use case. Using cloudflared means that your domain will resolve to Cloudflare's CDN instead of the real IP address, and all connections will also go through Cloudflare's CDN rather than directly to the actual device itself.