Thats cool. You should be able to tell if Atmos is working by playing an Atmos show/movie say on Netflix or another streaming service and check your Sonos app. If its atmos, it will show you Dolby Atmos on the app. 

BTW, just an update. I started having issues with Feintech VAX04101. When switching between AppleTV And FireTV, the 4k resolution would be lost. I’d have to shut down the projector, and unplug all sources and restart everything to get it working again. I returned the Feintech (again) and have the HD Fury Arcana working perfectly. It is a single source unit, but I don’t mind switching manually as long I get trouble-free video and audio. Has anyone else faced this issue with Feintech? Needless to say, my confidence in Feintech has dropped considerably after two middling experiences with their products. 

I use the Feintech VAX04101, albeit with an old LG TV, rather than a projector. It’s been absolutely fine. I use it with a Nvidia Shield, a Fire TV4K and an old Google Chromecast and not seen any issues. I have not tried the Arcana though, so can’t honestly compare.

The thing I will add is the VAX04101 is well built. I programmed its remote to work with a Harmony Hub so I simply use Alexa to switch its inputs (and the inputs on the TV too). So it all works without using a remote. Picture quality has been just fine, I get Atmos audio too and no lip-sync issues at all.

So I’m happy with their extractor. Mine did come with an EU power supply (I’m in the U.K.) however I had an old UK HDMI switch in ‘man drawer’ that had the same power input, so I swapped the power supplies over to save having to use an adapter. I have not (yet) tried doing any firmware upgrades, since purchase last year, so can’t comment on how easy that is to do, but I tend to leave things alone when they are working well anyway.