Thanks. A good suggestion, but I'm doing this both as a simple quick custom-cabling exercise, and then also so I don't have to pay or wait for more cables.
From what I've gathered, it seems not having the capacitor won't have any noticeable negative effect (correct me if I'm wrong). Second, the two wires that get combined into a single pin on the PSU side of the cablemod pro cable are the "Sense" pins, which are fine if they each go to separate ground pins at the PSU instead of being conjoined together into a single ground pin (which would mean only 7 of 8 pins would be populated at the PSU).
So, short of me overlooking something,, as long as I'm making absolute sure I'm correctly wiring source->destination pins (knowing that PSU-side pinouts are not standardized), I should theoretically be okay modding a 6-pin cable into an 8-pin connector, having the two extra sense pins (pins 5 & 6) each go to separate ground pins on the PSU-side connector.
Anything I'm missing or overlooking on this?