Traffic mirroring impact when target service is unavailable

I would like to know what is the impact of traffic mirroring on the cluster, especially if the target service is unavailable.
My problem is that I want to enable mirroring from production to staging, however this requires to tamper with production Virtualservice - if I patch production in place when i deploy staging, then a new production deployment will revert the change. Thus, i need to persist the traffic mirroring on the production virtualservice but staging environment is not always up.

So if the target environment of the mirroring is not up and the target service is non-existent, is there any impact on K8s cluster having mirroring enabled ?