Yeah, it's probably overkill but I think the multiple layers would help in cases I misconfigured something or if an account someone uses to log into Tailscale was compromised. For example when I ran the containers on a linux host I discovered later docker was bypassing the firewall rules and allowing all connections, but it probably wasn't a big deal because of the MTLS (and the server was behind a NAT router anyway so it was only addressable within the local network)