VMS100 Decora Stereo Self-Impedance Matching Slide Volume Controller
Using one or more of these babies on your 3 channel Sound system (Concertone or other) will allow you to manage your volume output for all three sources.
Putting two to work on channel A, (your surround left and right and rear surrounds) will allow you to compensate for overly loud surround effects that override dialog on the center channel.
Make sure you get the impedance matching ones to protect the Amp's output drivers.
I will volunteer as "mine canary" if you can wait till the fall.
This is another mod on my list.