This is what I use sans the DAC. RopieeeXL has been very stable with Spotify Connect so far. Volumio would be another option but I haven't tried it personally.
I had no idea that worked with Spotify. I've just built a second one with HiFiBerry dac and it's really nice, first one has the 7in screen. I'm using them as roon endpoints.
Raspberry PI 4 with a DAC hat (e.g. Hifiberry) running RopieeeXL?
This is what I use sans the DAC. RopieeeXL has been very stable with Spotify Connect so far. Volumio would be another option but I haven't tried it personally.