Again, I encourage you to look at [Link: remotecentral.com]
; most of codes are there. Look especially at Sound Field + and Sound Field - (45518 and 44494).
Here are some additional (or duplicated) possibilities.
Amp menu 29391
Auto Format Direct 64975
Amp Menu/Tools 28110
Remember, you need to be using Setup Code 31758. You can assign any of these 5 digit EFCs to a button using the 994 command just like you did in getting the OK button to work with the Vizio TV.
But read Post #2 in the above link. It tells you how to test and assign the various functions.