timed metadata support?

Is there any support for the media server to inject metadata into the stream, similar to what AWS IVS does?
https://docs.aws.amazon.com/ivs/latest/userguide/metadata.html

This is import to sync streaming with the user interface, as there is a 20s delay in streaming.

Start with the AWS IVS timed-metadata documentation linked in the issue and inspect the media server's streaming entry points. The issue does not name files or tests, so first clarify the metadata format, injection point, and synchronization expectations. Done would mean an agreed implementation scope and verified metadata delivery that can support UI synchronization.

Written by the indexing model from the issue text.