If you’ve organized your library folder according to the official naming schema, Plex should only touch each show folder to determine if the „last modified“ timestamp of the directory has changed since it’s been last scanned. No additional „heavy lifting“.
That being said… there’s already an existing suggestion thread discussing an option to flag single items or folders as „completed“, excluding them from future scans. Please comment/vote in that thread in order to help us avoid distracting or cannibalizing votes.
Unless I’m missing some unique aspect of your suggestion I’ll close this thread as a duplicate.
