How to script setting traffic policy for a new DestinationRule?

If I create a DestinationRule I need to know the setting for traffic policy. The bookinfo sample includes different versions of the DRs if mutual TLS was enabled during setup.

If I didn’t install Istio myself I know I can check the default mTLS setting with kubectl -n istio-system get meshpolicy default -o jsonpath="{.spec.peers[0]['mtls']}"

This only gives me the mesh default, not the settings for a particular namespace or service. I know I can start a pod and do istioctl authn tls-check. Is it possible to determine the traffic policy for a service without having a handy pod to pass to istioctl?