You can have effects on R2 but you need sysex to do it. Using XGworks (or XGEdit or any of the others) you can assign any DSP you might have to the midi channel that R2 is set to. On my 740 I have R1 set to channel 1 and R2 set to channel 2. I use any part (though part 2 is normally set to channel 2) and apply the DSP to it. Also with multipart you get a set of effects for that part - vibrato, reverb, chorus etc.

Bryan