Just thought I'd share with with ya.
I got my 3PK up and running with Dual ESC's this weekend, It works PERFECT! I set it up exactly as you had suggested and everything works just the same as the 4PK. I'm glad the 3PK was able to do this. I've had the radio for over a year and would hate to get rid of it!
Glad it all worked out for you Jesse "thumbsup" If you need anything else feel free to post up in here, almost everything on the 3PK applies in here as well.