to make the RJM work, the MFC must send on/off via MIDI to the right CC# values so that it'll switch
these are CC# 88 through CC# 95 for RJM switches 1 through 8 respectively
it don't look like these CC values can be changed in the RJM
so you need to look in the MFC manual to see if it is possible to send two different CC# values from the same IA switch
or...
send a CC# value whilst simultaneously changing preset..
I don't have the MFC manual to hand right now...
but I think this is thestudy / research direction you should head for..
EDIT: what I don't know is....
when the MFC sends MIDI to the Axe via ethernet, does this MIDI simultaneously leave the MIDI out of the MFC
you may also have a preset conflict...
I think the RJM can react to preset [program change] messages..
if this is the case, when you change preset for the Axe the RJM will change too..
so they'll most likely need to be on different MIDI channels
if the Axe is on 1, try the RJM on 2
I think what you're after is something like this..
you hit MFC: switch 1
this sends
- MIDI: PGM change on channel 1 to the Axe to call up preset 000
- MIDI: CC# 88 to the RJM on channel 2 to switch your amp channel [if RJM switch 1 is the one you're using]
you'd cable it:
Axe <- MIDI / ethernet -> MFC [channel 1]
MFC MIDI out -> RJM MIDI in [channel 2]
NOTE: I've never tried this so I'm just having a bit of a guess that could hopefully nudge you in the right direction