@jaquestati the PhotoTranscoder can go out of control unless managed outside of plex in my experience. For what seems like 2yrs now I have been deleting the contents of PhotoTranscoder via a cronjob weekly as if I don’t do this it grows unbounded. Stop and restart plex between deletes of this content. From what I understand it stores cached thumbnails for specific plex clients. Anyhow, deletion is completely safe IMO.
On metadata, once you switch over to the new agent and refresh of its data is complete make sure to run optimize and clean bundles. Clean bundles might take a few minutes to complete as it will delete all the old metadata from the old agent. See this comment from the alpha/preview thread.
