The Strich BT-N2 Bluetooth pedal works by following the instructions on SongBook section 21.1 and using mode/switch 2 (i.e. cursor Left/Right) on the BT-N2. I think mode/switch 3 (i.e. cursor Up/Down) is also recognised.
[ Initially I had the BT-N2 using mode/switch 1 (i.e. PgUp/PgDn) but that was not being recognised in SongBook. Neither were mode/switch 4 (i.e.Left/Right mouse click), or 5 (i.e. Space/Return) ]