Ahhh - ok. This mod , for me, came directly from Dale - he described it with pictures in great detail - where, I dunno, but I'm pretty sure it was on one of his triple or quad BLF EE A6's. With the insane DD multi emitter single cell lights we build, there's a lot of amps going thru the tailcap, like 10A+. He said he had experiences where he smoked the trace on the PCB board the switch is mounted on, so the purpose of this bypass mod is to eliminate the use of the PCB trace that might burn up from the high amps.
So it's not a mod that was done to lower resistance, but rather to save the trace from burning up. I think it's side effect though is lowering resistance by a very small amount. From my experiences, the weakest (highest resistance) part of a circuit will be the failure point, so for the EE X6 lights, most likely that trace is the weak point in the tail.
I've done this mod on the two multi-LED EE X6 lights I built. I think I did it on a couple of other lights. It's very similar to the tailcap mods we do on the SupFire M6 or other SRK style lights where we bypass the PCB traces. I've done similar mods to the battery carriers in lights like the Shocker. Traces on PCB boards, specially long ones, can't compete with 22 or even 20 AWG wires.