Thanks, Terry.
But this is not what I meant. When selecting PRESSURE as source in the modulation matrix, the synth reacts to "channel pressure". This, indeed, works well. What I was talking about is polyphonic aftertouch (few MIDI controllers are able to send poly AT). While many Arturia products also react to poly AT (best examples: CS-80V, SEM, ModularV), the Matrix-12V ignores poly AT MIDI messages.
By looking at those other synths, it should be easy to copy this bit of code also into the M-12V.
Best Regards,
Martin