State of logging to REE

What's the current state of being able to log to the REE using components that already exist in OP-TEE today? I've seen various issues relating to it in GitHub: https://github.com/OP-TEE/optee_os/issues/4230 and https://github.com/OP-TEE/optee_os/pull/810, but both ended up being closed before I can see anything relating to logging to integrated. Did something like this end up getting implemented yet?

Cheers,