ROLI Dashboard allows you to select the Seaboard's Press Mode, either Channel Pressure or Poly Aftertouch.
Since the Seaboard assigns each new note to its own channel, the musical result of using Channel Pressure and Poly Aftertouch will be the same, but some software can only respond to one or the other so the option is available here.
If an instrument or piece of software seems not to respond to the Seaboard's Press dimension of touch, try changing the Pressure Mode.
Both Channel Pressure and Poly Aftertouch are MIDI aftertouch messages which respond when pressure is applied to a key after the initial note-on.
Some software will not respond to both types of aftertouch, so ROLI Dashboard includes the ability to select one or the other. If your instrument is set to respond to aftertouch but does not seem to respond to the Seaboard’s pressure, try changing the Pressure Mode.
Channel Pressure applies equally to all notes being played on that channel.
Poly Aftertouch can be applied in varying amounts to each note played on that channel.
Since the Seaboard uses multiple channels and assigns each note to its own channel, there is no performance difference between Poly Aftertouch and Channel Pressure: there is never more than one note being performed on a given channel.