Ok, midibridge does work, but what happens when you need to use a midi foot controller and iRig?
If the footpedal does not have a midi merge feature that works with sysex messages, then you'd need a midi merger to combine the iRig MIDI Out with the Footpedal MIDI Out. Like this:
iRig MIDI Out -> Merger MIDI In #1
Footcontroller MIDI Out -> Merger MIDI In #2
Merger MIDI Out-> AxeFX MIDI In
AxeFX MIDI Out -> Footcontroller MIDI In
Footcontroller MIDI Thru -> iRig MIDI In
MidiBridge is able to route and merge MIDI. One would need an iPad compatible 2x2 MIDI interface to do this, and this interface has support sysex and has to to be compatible with MidiBridge.
I think it just might work, like this:
Footcontroller MIDI Out -> Midi Interface In #1 -> Midi Bridge
AxeFX MIDI Out-> Midi Interface In #2 -> Midi Bridge
Midi Bridge -> Midi Interface Out#1 -> Footcontroller MIDI In
Midi Bridge -> Midi Interface Out#2 -> AxeFX MIDI In
Make all the necessary routings inside the MIDI bridge app.