Just found another error in the docs, the instructions for the alarm wiring for the pro look like they’ve been copy-and-pasted across from the standard board:
Positive Terminal: Attach the siren’s positive (red) wire to the ‘OUT’ terminal on your Konnected board.
Negative Terminal: Connect the siren’s negative (black) wire to the ‘GND’ terminal.
These don’t exist on the pro, it should refer to ALRM1 and ALRM2, and it looks like what’s switched is GND, not +12V like on the standard board.