I was an early adopter of Jellyfin and love it - but personally prefer Navidrome for my music server. Granted, I haven't looked at the music capabilities of Jellyfin in a long while, because I've been running Navidrome.
Symphonium android client is my recommendation for that (and I believe it also works for Jellyfin) but there are others.
My pipeline is essentially as you describe though Lidarr --> nzbget --> Navidrome