Using both and HDMI and Displayport connection on the same Display

Hi all. I'd like to connect my MBP to my display via Displayport to get reliable 4K @ 60Hz video and I'd like to get digital audio from my receiver through HDMI (using Apple's AV USB-C adapter).

While I would like to only transfer audio to the receiver, HDMI transmits both audio and video. In my case, however, the HDMI-out from the receiver will come back to the same display as the Displayport connection.

What I want to avoid is the MBP thinking it's running 2 displays (through both DP and HDMI). Any advice?

Thanks in advance!