ok it can be done...but note* your going to get a latency on that mpx 1 that will render your fx box just about unusable. What you have to do is add your mpx-1 as an input buss. Let's say 3-4. Turn direct monitoring on. And then route the tracks to that buss. To tell you the truth I wouldn't attempt this though unless you get vers. 3 which came out yesterday. They've put in a feature to allow you to do this and they've added delay compensation to account for the latency. The only hitch? 150 to upgrade.
"you bust your ass to make all the money you can...thinking it solves shit...and then you realize..when and if you get there at all...you got more problems and you missed out on the one thing you can't buy or get back...your life! Spend time with friends and family...You can be broke in other ways too!...."