Using Some "'Local Media Assets", but not Others (Title)

I have downloaded all of the Adventure time episode title cards, and named them appropriately ("-thumb"). I really want to use these, as they are way better than the random screenshots on TVDB.
But whenever I position the LMA agent to display my local episode thumbs, it also used the file’s title value (and who knows whatever other metadata garbage that was encoded in the files originally).

How can I have plex use the local thumbs while using TVDB’s title and everything else? Is this possible?

Unfortunately not.
With LMA it is all or nothing.
If you want your custom episode thumbs that bad, remove your files’ embedded metadata altogether.

On Windows, mp3tag can do this with a whole folder of mp4 files at once if you want.
(And it also can ‘optimize for streaming’ those mp4 files afterwards, which sometimes makes the difference between Direct Stream and Direct Play [the latter working much better when Plex Server and client are poorly connected or are very far from each other, geographically] ).

‘optimize for streaming’
What are the downsides?

@wisnoskij said:
‘optimize for streaming’
What are the downsides?

It may take a long-ish time to do it, because it has to write the complete file anew.