Maybe. Seems a premium model could allow more real estate to fix that. Then again, I look at Marantz over the years, and their performance in the end has been very consistent. So much so I doubt with all the changes the noise just happens to make the same near exact difference.
Couldn't an AVP be made where everything was kept like it is now, except zero conversion from digital to analog. Then when everything is ready a digital connection sends the data out to a multi-channel DAC. Pro recording gear manages to get this to work very well. Such a device might cost more, but at least it could have excellent audio results. Video is already HDMI and digital video is almost wholly sent to display devices where it is finally converted. Seems the same could be done for the audio side. Have your complete AVP with digital video outs and digital audio outs both converted elsewhere.
It's possible, I suppose, though it would likely have some impact the way that the digital processing might work between two channel and multi-channel operation.
What you suggest is totally logical but would have cost implications that would affect the profit ratio of the devices. I think AVRs are the cash-cows of the lo and mid-fi sectors of the audio business. There's great profit to be made as long as they are designed to perform in a very limited way. Go beyond that, with low noise power supplies, extensive shielding, better cooling, and discrete assemblies and their prices rise to the point that they cannot meet their sales targets.
This lesson was learned with VCRs and R2R. The wonderfully constructed ones didn't sell, so the construction methods got cheaper and cheaper until noise and tracking met the needs of people who didn't know/care better. It reminds me of how Colin Chapman settled on the design for the Lotus 7 chassis: He build a strong tube chassis. He removed tubes one at a time until the chassiscollapsed. Then he put the last tube back.
The crime is that to meet their sales targets, AVRs are marketed as hi-fi devices. That's why folks like Lonnie don't want to see them or their digital stages judged by the same meter as audio components. Doing so risks exposing a beautiful lie.