Yes you can make NEW circuit OUT wiring to be the left pad of R6 (looking at board front). You can see on the back of the board it is connected to Volume Pad 2. This matches with the schematic. Obviously you would not need to populate any components on the board after Volume (schematic wise). Finish by running the wire from the left pad of R6 to Lug 7 of the foot switch or BO of the 3PDT wiring board following our wiring scheme.
Again checking with the schematic you can avoid the hot switch by not populating R3 and using a jumper between switch pads 2 & 3.
I hope that helps.