Hey @Georgethesixth,
Did you get this worked out? We don’t have any Devialet hardware in our test lab to confirm, but your settings look sensible to me.
I’m not sure how Devialet handles volume control unfortunately – I can tell you Roon doesn’t don’t do any volume attenuation, so if you’re connected via USB and controlling volume successfully, I think you should be in good shape. You can find more details about how Roon handles volume control here.
Let me know if you still have questions here and we can take a look Joris. Thanks!