Okay, I'm intrigued. Are the custom built RFID cards physical manifestations of albums which you can use to select and play a given album hosted with Navidrome? I'd love to see your setup/some examples.
I have found it is great when people are over as everyone gets to dig through a huge collection of cards and take turns playing their favorites.
I wrote some customer software but it is pretty basic. Basically read the ID of a card and play the corresponding album.