This functionality used to work. With the current version of SteamOS 3.8 which uses flatpak 1.16.6 it was observed that if one decides to, e.g. trash the libreoffice user data folder, nothing happens, the folder is untouched.
If one uninstalls the app, the user can still delete the leftover data with flatpak uninstall --delete-datain the terminal.
This functionality used to work. With the current version of SteamOS 3.8 which uses flatpak 1.16.6 it was observed that if one decides to, e.g. trash the libreoffice user data folder, nothing happens, the folder is untouched.
If one uninstalls the app, the user can still delete the leftover data with
flatpak uninstall --delete-datain the terminal.