I learned something: jellyfin is a forked emby. Not sure why emby was forked or why you’d choose jellyfin v emby.
NOTE: I do not use SCLE or docker so this could be bad advice.
I posted this thread in the hopes it would be relevant to docker apps as it is to jailed apps on CORE. I hope the following can help in some way. If not, sorry.
Plexdata backup method - TrueNAS General - TrueNAS Community Forums