Hello,
just to share a little experiment I’ve made which really made my day 
I was actually more interested in the reverse setup than the one described in your like : having the slave running on my PC while the mod runs the master. So I wrote the following script, which allows me to record on my PC the signal coming from the MOD and to playback anything from the PC through the amp plugged in the MOD (my keyboard, via QSynth for instance) 
EDIT : As you can see, it is quite customable to your needs. One could add more channels and push sounds from the PC to any intermediate effect in the pedal-board (or reversely, collect it back to the PC). For a full list of available ports, use 'jack_lsp -cpt" on the mod. I have not tried yet, but I suppose MIDI forwarding should be doable too (for instance to control the starting/stopping of the recording on the PC from the MIDI controller plugged in the MOD, if your DAW allow it). I suppose a nice thing to have in the future would be a GUI on the PC side to add/remove/connect ports as you go.
#!/bin/bash
pgrep "jackd$" > /dev/null && echo && echo && echo "Jack seems to be already running. Please stop it before running this command" && echo && echo && exit 1
sshpass -p mod ssh root@modduo.local << EOF
jack_load netmanager -i "-a 192.168.51.1"
EOF
jackd -R -P 80 -d net -a 192.168.51.1 -C 2 -P 2 -i 0 -o 0 -l 9 -n connected-pc &
sleep 5
sshpass -p mod ssh root@modduo.local <<EOF
jack_connect connected-pc:from_slave_1 system:playback_1 && jack_connect connected-pc:from_slave_2 system:playback_2 && jack_connect connected-pc:to_slave_2 mod-monitor:out_2 && jack_connect connected-pc:to_slave_1 mod-monitor:out_1
EOF
jack_lsp -cpt