This seems to be the only way to request features from the plex team (I assume they read these?) so here goes…
It would be fantastic to be able to disable episode thumbnails being generated by plex for a particular library. I often use plex for watching sports, and for some reason plex insists on grabbing a frame from NEAR THE END (!!!) of the media file, which seems bizarre, and is a total spoiler fest for pretty much any kind of sport. Plenty of others are complaining about the same thing, e.g:
There is a hacky workaround (manually creating a jpg named the same as the media file and putting it in the same folder) but a simple tickbox on library settings would seem to be a trivial addition to plex and would stop it from spoiling the results. Or, why can’t it pick a frame from near the beginning?