Is there a reason that you don’t organize your music by artist\album and leverage tags? It’s been some time since I tried Jellyfin, but Plex does an excellent job of tagging (not directly written to original files) and categorizing. It’s a good experience.

You should not be using NAT to access your Plex externally, I will explain.

App.plex.tv and the apps use Plex services to generate a point to point connection from remote clients through your router to the server. This is important because you never need to expose a private IP to the Internet, and the authentication can be protected with something robust like a Google account which support 2FA and even phishing-resistant 2FA.

The combination of more advanced security and secure/convenient SSO authentication are one of the biggest benefits of Plex in my opinion.