General multiport MIDI router patcher

I have been trying to use MainStage 2 which supports external MIDI devices to manage my live keyboard rig. Unfortunately, MainStage 2 has a bug where occasionally a MIDI note event gets sent to the wrong external synth. (NB, I verified that this problem was MainStage2 related by creating a very simple router patch in Max that routed multiple keyboard to the desired synths in exactly the same way as I was doing in MainStage2 and it worked perfectly. Also created a simple multi-port input sequence in Digital Performer and that worked perfectly as well)

Now that I have established that the problem is MainStage2 related, I've started thinking about just using Max to manage routing.

So essentially, I would like to have a simple way to select a "patch" and that would cause a particular routing of various midiin to midiout objects and ideally could also send program change (and bank change) messages to each output.

I'm sure I could probably build this given lots of free time but I don't have time to figure it all out. I'm hoping that somebody has already built such a patcher, free or commercial, that I could get.

TIA

D