This makes ALL the sense now, ha.
SW on PCB to LED K, no beep.
3PDT lug 4 to SW pad on PCB, BEEP.
3PDT lug 5 to ground, BEEP. (in both modes)
In effects mode, 4 and 5 BEEP. When not in effects mode, 4 and 5 no beep.
For sure it is SW PAD on PCB to LED K no beep! Amazing way to deduce...