Pass-through Roon Endpoints

Is WiiM Pro a certified Roon endpoint now?

Yes.

Or are you streaming from Roon to WiiM using AirPlay?

No. Roon to Wiim Pro is over standard Ethernet, Cat7 cable to be precise.

How are you streaming to Bluesound?

Via home network with WiFi.

How is all this set up?

NAS with local files, connected to home network via Ethernet; MacMini (M4) on Ethernet runs the Roon Server. Active endpoints include Wiim Pro (Ethernet), Bluesound Node (WiFi), a MacBook Pro computer (Ethernet), and an Apple HomePod (WiFi).

What sources are you using? Qobuz, Tidal, Spotify, local music files? 

All of the above except for Spotify.

Worth mentioning: I'm in the process of upgrading part of the system now. Look like I'm going to be replacing the Wiim Pro in the main downstairs unit with a HiFi Rose RS130. This should be a big, big change.

When I tried WiiM Pro it wasn’t yet certified with Roon. Good to know they finally got that done. It’s an OK streamer with Qobuz and Tidal but I wouldn’t put it in a system with B&W 800 series speakers. 
 

What you need to consider is the following:

1. When you have your streamer connected to the DAC via coax you rely on the clock in the streamer. Given the price of WiiM we can safely assume the clock used in this unit isn’t anything special. It’s almost always best to use USB to DAC to rely more on clock in the DAC. With most modestly priced streamers you will get better sound using USB. 
2. Your Roon Core matters. 
3. Digital cables including Ethernet cables matter 

Rose should be a nice step up. 

Update: the HiFi Rose RS130 died after two weeks so it's back to Crutchfield for a refund.

I'm using a recent-model Bluesound Node in digital passthrough mode in the RS130's place. It doesn't have the cool screen. But -- full disclosure here -- I can't hear one iota of difference between the Bluesound and the RS130.