Quite a while back, I had some suggestions for the 990 successor.

http://ubb.outlawaudio.com/ubb/ultimatebb.php?/ubb/get_topic/f/34/t/001195.html#000022
1. An overall limit on output level with individual input level adustments:

http://ubb.outlawaudio.com/ubb/ultimatebb.php?/ubb/get_topic/f/7/t/000221/p/4.html#000147
2. I was thinking of doing audio only with lip sync, keeping video separate. Obviously, audio and video will be together for the 997.
a. Would it be possible to control audio separately from video? I can't stand the network commentators when watching the (often pitiful) Vikings, so since I send all my HDMI through a separate switch, and use the 990 for audio only, I can listen to the audio from the local radio station, with the Squeezebox. There are other occasions when I separate the sources.
b. If you are considering a lower cost version of the 997, would it retain all the 997 audio goodness, but be audio only (with lip sync)? Wouldn't that be a long range guess!