stats_cb does not seem to be supported. Is there a particular reason for this or just simple matter of coding?

Other than implementing that is there any other way to get the statistics? I'm mostly interested in queue sizes, transmitted messages and errors per topic. KIP-714 which I think can be configured for librdkafka, on a quick read, does not seem to include these, but maybe I'm mistaken. Having locally exported metrics would also allow adding custom/pod specific labels to the metrics