Let’s not forget these projects come from the same company that
1) had a so-called recycle mode in their devices that bricked them with no undo option,
2) lately requires you to create an account on their site just so your networked speakers may work at all.
You know how many internet accounts I need to take a raspberry pi, a USB DAC, hook those to a fine pair of Edifier speakers and run shairport-sync?
NONE AT ALL.
Heh, the thoughts are similar but not that similar.
https://github.com/mikebrady/shairport-sync
It actually does implement multi-room synchronized audio. This was the one thing keeping me from running an OSS audio solution using RPis. I like that it runs AirPlay, so it can "just work" using existing devices, and not a crazy uncle solution.