I just installed the veto rack this weekend. The few departures from your procedure that I did were:
I drilled two 18/64" holes in the fender about 1 inch from each side of the brake light and routed the turn signal wires through these holes. I did not have to extend the wires. I added silicone sealant around the wire going through the holes.
I also filled the wire tube of the turn signal with silicone sealant to keep out water. This end of the tail light was in a protected area and is now out in the weather.
Everything else went according to the plan.
04 GL1800A - Traxxion suspension
11 DL650 ABS white - Lowered, Risers, Richland Rick stuff, Sgt seat, Madstad