The documentation for extensions.filters.common.fault.v3.FaultDelay mentions that it can be used to "delay proxying of TCP connections"; but as far as I can tell, no such filter is implemented for TCP.

As far as I can tell it is a relic from envoyproxy/data-plane-api#192 where TCP fault injection was originally defined (but dropped in a subsequent commit in the PR).

I'm still kind of hoping I'm wrong about all of this 😅 but I think it is just a doc inconsistency.