I use Apple Music and have made a very similar setup to the article. Instead of the NFC pointing to a Plex URL, I have it trigger an Automation to play the relevant album on Apple Music. Works well, plays instantly, feels magical, and most of all it's got rid of the 'what should I listen to' friction so I now find my home is filled with music way more often. Downside of this approach is it only works on my own phone.
This article (not mine) explains the Apple Music/Automation approach – https://hicks.design/journal/moo-card-player