Hi,

technically, yes… you can use AirPlay from your Mac to Ray, but I would guess there would be some latency in the audio.

this works well for occasional use, but unless things have changed on the AirPlay side of things in MacOS… it drops the connection after a while of inactivity (~15mins IIRC)

the other option, if cabling allows, would be to use a USB sound device that outputs Optical between the Mac and Rey…. That would be a more “always on” solution 

Often PJs are a problem with Sonos. You don’t say which PJ you have, but if it has optical output then just plug the Ray into that. If the PJ lacks optical output, well then that will be a problem.

On the positive side, HDMI switches that have optical outputs are fairly common, and mostly inexpensive, should that projector not have its own optical out. If you peruse the Home theater section of these boards, you’ll find quite a few posts about that functionality, although many might be slightly older, posted when talking about the PLAYBAR, which also was optical only, like the Ray. 

Thanks all. 
 

If I buy a Beam instead, is it still the same issue with wireless audio stream from a Mac?

Yes, same issue. You would still be relying on AirPlay and that is the issue. It is just the way Apple has implemented it.

I tried an Original HomePod and it behaved exactly the same.