[Baertram]

I've found the folders of live and PTS and one of this folders (live) was created even in September 2023 already o0

Sad it's going to stay in that AppData/Local "hidden folder". Whatever reason ZOs got here, it's disturbing backups and access (explain casual users how to access it if they cannot see it? You always have to use a direct link or the %appdata% constant, and even this brings you to the Roaming folder and not the Local one).
-> Or are backups not really possible with those local cache history files? Like copy the files today to another directory and paste them back tomorrow, and then get only missing events/entries from the server of yesterday to today.


One must use something like this to access it then:
%USERPROFILE%\AppData\Local\Elder Scrolls Online\live\CachedData\GuildHistory