Navigating between Pedalboards within a Bank can be accomplished by using the Duo's Foot switches or by sending MIDI Program Change messages along a designated channel (default is channel 16).
Note that if one of the Foot switches is already assigned to a control, the navigation with foot switches option won't work (file bug?)
Pedalboard navigation only works when the web interface is not connected. With the web browser disconnected, go to the Settings menu on the Duo and load Banks. When you select a Pedalboard within one of the Banks, navigation will become active for that Bank.
It is not possible to replicate the same increment / decrement functionality with the Program Change messages as with the foot swithces.
When using the Program Change messages, each value corresponds to a Pedalboard within the Bank. The first Pedalboard is at slot 0. The second is in slot 1, and so on.