Sorry--my mistake. I mixed up the subdevice number for Power toggle, and as you describe, the EFC for Power toggle has to be assigned using 30842.
The remote has a Volume punch through capability, which is described in the instructions.
To have the Vol +/- buttons always send a signal to the Onkyo:
1) Press Setup until 2 blinks
2) Enter 993 (2 blinks)
3) Tap AUX.
The remote will blink twice if the procedure was successful.

You can read about many of the 9XX commands at www.hifi-remote.com/wiki/index.php