Sorry, I wasn't targeting you for anything - you may not assume anything but others who read threads like this will do. This is precisely the deal I mean.
Is audio.device supported in OS4? Yes, it is. Had this been run on a real Amiga the question wouldn't have even come up. It all adds up to an undeserved negative perception of AmigaOS 4, when the fault is somewhere else.
My mistake about the sound card - I was forgetting that audio.device was a Paula thing and not AHI. Paula is definitely] supported in AmigaOS 4, though.