I know most of the talk in the thread was implementing Roon, but since the thread has already been brought back, here's a basic option for future reference...
For a simple AirPlay 2 streaming solution I use the Belkin Soundform Connect. I run the optical digital out to my DACs and am good to go. It's super convenient, especially in my home setup since I can stream from the iPhone, MacBook or when Lauren hides from the kids in my office, she can use her phone as well. I run one at the office, too. My only issue is an AirPlay issue more than Belkin's implementation... If I pause it for too long when using the phone, or multitask when paused, it reverts back to playing on the phone. I think it needs a longer time-out window. With the MacBook, it maintains that as my preferred audio output without issue.