Tired of listening through the browser, I found Radio for Mac [2] which allows you to play streams - DI publishes the stream address for all of its stations, so you can pipe these into Radio and hence listen to their music without needing a browser open.
Radio also has a recording feature - a stream can be recorded and saved as an mp3 file. After a few months of subscribing to DI I noticed they were simply repeating the same (few hundred) tracks on each station. So I set up my Mac to record a few stations over the course of a month, so I could listen to the tracks when offline (with Tiny player [3]). Since I was listening to the same songs over and over, I started to question whether I needed a subscription to DI any more…
[1] https://www.di.fm/ [2] http://radioformac.com/ [3] https://www.catnapgames.com/tiny-player-for-mac/