I'm OK with structuring file layouts however it wants. I'm even OK with giving Jellyfin a whole directory tree full of symlinks that are organized exactly how it desires, and then automating its ongoing maintenance.

The thing I'm not OK with about Jellyfin is that the common answer for remote access involves setting up a reverse proxy or a VPN or some other darned thing that I will never be able to talk my mom into configuring her Roku to be able to use.