Since emerge outputs many different kinds of warning messages, it is important to clearly indicate when those messages are non-fatal, in order to ensure that they are distinguishable from fatal errors. Maybe a prefix like [WARN] would be helpful for this.
The message from bug 472104 is one that might be displayed with an [INFO] prefix.
My elog PR should be good enough for this. It's a bit of compromise between verbosity and short output as it uses two-letter codes but this should be good enough to distinguish them.
I'm still interested in this (see mgorny's PR and the version I rebased) but it's fair to say it's not being actively worked on right now, so back to CONFIRMED.
Heh, apt seems to be adopting this kind of thing: https://www.phoronix.com/news/Debian-APT-2.9-Released.
