However, while you can never really trust anything you run with internet access, I feel there's a fundamental line between an explicitly cloud-dependent service like Tailscale (e.g. a Tailscale control server outage incident would impact your home server access) compared to a fully self-hosted service that may or may not phone home if you don't put preventative measures in front of it, but will continue to function fine if you do put said measures in place.

The Asus mobile app is another potential concern but the Merlin browser UI is fine for most purposes.