Is there a way to tell Plex to generate thumbnails for new content only?

Didn’t see this posted, but sorry if this is a dupe.

Would be nice if Plex had a feature to enable thumbnails for new or changed content only, not existing. I don’t want/need the server to churn through my backlog of content but it would be nice to have thumbnails for future content. As far as I know this isn’t possible today unfortunately.

Create a new library, and add new media to that
Then enable for that only

Appreciate the response but not exactly what I’m looking for. I have a lot of libraries organized in a specific manner with various automation for managing things. Just hoping a “enable but grandfather existing” option existed, or maybe the ability to put a flag file at the root of a movie or tv show, e.g. nothumbs.flag

Early 2021 clean-up: duplicate