Question about WiiM Amp

As I understand it, WiiM Amp cannot decode multi-channel sound systems, only stereo signals. The AV receiver would therefore have to output exactly the two additional channels. The volume and equaliser of these two channels would then be controlled by the WiiM Amp. Even if it worked in principle, the joy of this solution is likely to be limited.

I have no idea, I use the device as a stereo amplifier.
But there are lots of tests and device presentations on the Internet. I think you'll find what you're looking for there.