On real Receivers, you're right; while it's impressive that that HomePNA stuff worked at all, it never worked as well as it was supposed to. (Receivers have Ethernet too, which is certainly capable of streaming WAV, but we thought HomePNA users would be in the majority, and didn't want to make them second-class citizens.) For Receiver Edition, it works fine, although you need a server that's prepared to give you the WAV files in the first place. Most don't, as they're intended for use with real Receivers which can't "decode" the WAV format even if they could stream it fast enough. With a custom server, I've decoded Freeview DVB-T radio on the server and sent it as WAV to a Receiver Edition car-player.

If you're still worried about WAV bandwidth, the Receiver Edition is a v3 build, so you could send it FLAC instead.

Peter