Yeah, I feel ya.
All my TV shows had carefully downloaded, high resoultion DVD cover art. If a season had multiple disks, each episode was tagged with the correct disk of the collection, i.e. episodes 1-4 had the right disk associated with them, as did 5-8 etc.. I did NOT want a thumbnail from each episode - I think a still from the action didn't really help much, and looked ugly. Then it was arbitrarily decided that that wasn't right and that TV episodes needed to have thumbnails if you wanted to get the other metadata.
Now you have the option of choosing not to get the thumbnail, but only if you collect the data for each file manually. Not going to happen with over 10,000 TV episodes in my library. In the end I decided that the metadata were more important to me than the cover art, so years of painstaking downloading of dvd covers went down the drain.
I've asked several times for us to be able to at least have the same control that we do in individual look-up mode in batch mode. I.E. To select a bunch of files, do a look-up and be able to decide whether we want the image file, the data or both associated with our videos. I'm dealing with the thumbnails instead of cover art now, and although it has less of a frosty reception than it once did, I'm still not sure that I'll actually enjoy it ever.