Runtime configuration of HTTP fault injection per upstream cluster

Title: HTTP fault injection filter can have runtime settings per downstream cluster, but not upstream cluster.

Description: I'm trying to simulate a failure of an external service. In my case, fault injection filter should be configured as one of the egress http filters to inject delay or abort requests to the external service. I want to inject failure only to the requests to the specific upstream cluster (the external service) in runtime. But as described here, fault injection filter allows runtime setting only per downstream cluster by , not upstream cluster.

Thanks