I have the perfect answer for you as I was just asking the same question a few days ago. This is an open-source and free software that allows you to RIP audio from Tidal, all you need is a Tidal subscription (either tier works.) It’s incredibly easy to install and works almost perfectly. It works as of yesterday and I’ve downloaded about 2800 FLAC songs onto my DAP.

I bought a Sony NW-A55 which uses Sonys custom software. I originally was going to torrent all the albums I listen to but that’s not working out for various reasons. If I were to get one of the nicer ones that run on android, could I install Apple Music and download my music onto an SD card? I assume the answer is yes, but the real question is if I can download the music in a lossless format like I can do with my iPhone. I’m not sure if the google play version of Apple Music allows for lossless audio, I have yet to figure that out.