the user just wants to use another preamp with the poweramp of the schmidt (you want to switch between both preamps and use the vh4-poweramp). he needs the jack in the input of the schmidt cause peter implemented a hardware-mute: when there is no jack in the input there will be no sound at all. so in the schmidt case he uses a jack in the input to unmute the amp, but goes: guitar --> preamp-in, preamp-out --> schmidt return. so he uses guitar-->preamp-->schmidt-poweramp.
in your case i'd start with this:
guitar --> vh4-in
vh4-thorugh --> jmp-in
jmp-out --> vh4-parallel-return
switch-midi-out --> jmp-midi-in and jmp-midi-ot --> vh4-midi-in
jmp-sound:
patch2: jmp normal sound patch
vh4-channel-insert=on (perhaps you need the blind jack in channel1-insert-send)
vh4-parallel-loop=on
vh4-parallel-loop-vol=full
.gif "guitar :m17:")