> Note that Plex media system generates also thousands of thumbnails with
> very long name or path

Plex is a media server which greatest feature is to automatically classify and content-enrich media based on retrieved information, classification, description, and thumbnails from various web sources, resulting in a "netflix-like" personnal media center
https://plex.tv/

Some stats about my Plex Media Server cache:

284,653 files
19,105,279,728 bytes
953,329 directories (!) (Note that two third of directories are empty)
It actually takes up to 10-15 minutes for ZTree to log everything first time.

On these, 172,510 files have a path equal or greater than 150
60,042 have a path equal or greater than 180
410 have path equal or greater than 200
Longest path is 203
Longest name is over only 77

For performance issue, I installed cache and program on dedicated partition

Actual cache root is W:\Plex Media Server\
With standard default, it would have been C:\Users\Laurent\AppData\Local\Plex Media Server.

Which would mean longest path would be +28, that is 231.
Even longer if Windows user name is longer.