Overriding ELD/audio config settings from HDMI?

I have several htpcs with nearly identical setups so the following really applies to them all…

My nvidia card connects to my 7.1 surround receiver via hdmi. Then my receiver is connected to my tv. If my tv is on when the nvidia driver is loaded, the ELD is reported as only having 2 channel stereo audio available. If my tv is off, the ELD reports 8 channel surround available.

Is there any mechanism to override the audio portion of what gets reported via hdmi? I want to ignore what the tv reports and only use what my surround receivers reports but I have no clue how to do that, or if it’s possible. I don’t even know where the audio config comes from but it must be received via hdmi. Is it contained in EDID? Does anyone know how to force a specific audio config? Can someone offer some clarity on how this works? I originally inquired about this on the alsa mailing list but was told the contents of /proc/asound/cardX/eld#Y.Z is just showing what is passed from the graphics driver.

Thanks for any help!