How to give Jellyfin read-only access?

[HerrRay]

In the mean time, while perusing the Jellyfin forum, I came across this very interesting guide: https://avalon.christianrybovic.ch/ and the author seems to be pretty knowledgeable (perhaps he's a forum member here too, I don't know). He does things with groups and users that I didn't read elsewhere (including the TrueNAS docs, though it could be easily the case that I didn't read things properly, also I'm not very experienced with TrueNAS as of yet). The read-only problem is addressed in various ways, including the standard docker image settings for Jellyfin that includes that very checkbox... In terms of tuning he also brings up an interesting point about the record size of a dataset. Based on what I read about ZFS, for users with very large movie sets and thus many database writes when scanning for metadata for instance (I mean the Jellyfin database) it seems to me that this number should be indeed scaled up for datasets with large videos and scaled down for the config and cache dirs (the latter also preferably on SSD disks) but please correct me if I'm wrong!