Question about trickplay files

[Rufufu]

Hello,
Because my server randomly lose access to my USB drive, it often deletes all my library, in particular trickplay files that are long to regenerate.
I have decided to change the setting to store trickplay files on the media folder, so I won't have to regenerate them if a have to rescan my entire library.
With that setup, what happens when radarr or sonarr update a file, or when I manually delete a file in radarr? Do the old trickplay files gets erased ?

[jellykrabbypatty]

I don't use sonar or radar, but I strongly advise to go to your media drive and search by "trickplay" and just copy all of them as a back-up. Those things take forever.

[Rufufu]

I am afraid it would take as much time to regenerate as to manually copy back the trickplay files at the right location... Usually, I can recover everything with a Timeshift backup but this time it doesn't work I don't know why... It takes me 4 days to generate trickplay files for my 10 TB library on my setup, what bothering me is the additional power consumption as I have a low energy budget.

It makes sense for me to have the trickplay files on the media drive, however I am concern about the maintenance of it on the long run, as *arr are updating files regularly... It seems Jellyfin is very conservative and do not delete them, but I am not sure (I can't test it for now as the trickplay files are being generated right now).

What would be the best approach for a regular clean up? I don't have the know-how for building a script that do it. I plan to switch the setting for trickplay file location, to let jellyfin moving all the files to the library SSD, to remove all remaining traces of trickplay files on the media drive, switch back the trickplay location setting, and let jellyfin move the files. Does it seem right to you?