Gosh, you went to a lot of trouble to produce such a clear and nicely formatted report!
In a similar vein, as I described here before (and am updating now)
, for about 80 bucks I threw together an electronic remote/intervalometer for my 645AFD, using a JYC RS-60E3 for Canon and a Quantum 467 coiled cable for Mamiya 645AF. No cutting or soldering required - just a 2.5mm stereo socket T-junction between them. The Quantum 467 cable is "mono" so it requires 2 presses of the remote if the camera has gone to sleep. But I may "upgrade" to the alternative Quantum FW45 MD "two step" cable, which is "stereo" and the 2nd pole should provide instant wakeup
. I suspect that this is what the unused white wire described in your report would have been for.
Actually, it seems that the only reason why you had to cut and solder, was because the Profoto cable you used ends in a 3.5mm jack rather than 2.5mm? In that case, using the Quantum cable could spare you that trouble. My exact approach (substituting the GigaPan Canon cable for the JYC RS-60E3 Canon cable...both are 2.5mm/2-pole) would do the trick, I think.