Figured something out. In case someone else needs it, here's what you do:

First, set the Rotor contoller to HH2 mode (i.e. this tells it to use Pioneer CD IR codes)

Then you can use a discrete-off for a Pioneer CD player to turn the unit ON. The CD discrete-on also works to turn it on, although in my case, this would also power on my CD player.

There is no direct discrete-off (the CD-player discrete off will still turn the unit on). Instead: issue a discrete-on, followed by a toggle power-off from the UDB.

If someone needs this, and doesn't understand - email me: [email protected]