Even in this case, you still need to have a node somewhere to run the container and store the WireGuard keys, to be able to link the tailnet and the WireGuard endpoint. So that single point of failure still unfortunately remains.
The benefit of having it all configured in a single container means it's pretty easy to spin up anywhere (where the fenced router is accessible), all you need is the tunnel config file.
I also wanted to make sure it works for both IPv4 and IPv6 connections, because many ISPs in my area are starting to only give public IPv6 addresses. That way as long as the WireGuard router has IPv6 and the node running the container has IPv4/IPv6 dual stack, one can still access the Wireguard from an IPv4 only device.