An extra HDMI output for Audio only. It's been gone for a few years. It used to enhance the playback options. Will it ever return? Does anyone else miss it?
No one is going to make a product with an "audio only" HDMI port at this point (its not within the spec).
Perhaps if you describe your setup/the issue, we can provide more help.
In lieu of that, I suggest an HDMI splitter/audio extractor: