There is some stuff missing (e.g. touch /config/auth/tailscaled.state doesn’t work without first creating /config/auth) and there is the auto-update functionality of tailscale tailscale set --auto-update which may suit your need as well instead of manually updating.
Lastly Ubiquity stopped using /config and instead is using /data now, I would honestly recommend just using this script: GitHub - SierraSoftworks/tailscale-udm: Run Tailscale on your Unifi Dream Machine