I did find a small workaround. I can set HDMI on my gpu as either main or secondary display. Then I can send that + audio to the SR6007. With the SR6007, I can set it to passively output whatever is on one connection, in this case the one from my GPU. The other monitor is connected via DVI. Now, if i turn off the receiver, after a rather unflattering session of the screens blinking and figuring out what is going on, both screens display the same data.
I also set both monitors to SRGB colorspace. This makes them both match up almost perfectly in terms of color. Any color adjustment can be done through windows color profiles.
The only thing i havent figured out is the proper HDMI audio configuration for my computer. 5.1, dts, and dolby source files play correctly on the receiver. They are sent to the receiver as 5.1 PCM 3/2/.1, DTS 3/2/.1, or Dolby 3/2/.1, respectively. But 2.0 channel audio is also sent to the receiver as 3/2/.1 PCM unless I use wasapi (and in that case it is correctly sent as 2/0/.0). 2.0 source files are the only thing that arent sent to the receiver correctly at this point.
For the time being im just using s/pdif and dts-interactive from my sound card as I only have 5.1 and dont need the hdmi audio yet.