Hmm... it's a long long time since I did any physics, but I seem to recall being told that current is like water and finds its own level. The signal is "carried" by the current I suppose as a modualated sine wave and when it reaches the loadspeaker voice coil is converted back into mechaical energy which vibrates the diaphram and appears as sound waves. I guess the current per se keeps on flowing round the circuit provided the circiut is closed, ie the mains is switched on, and there's an input signal being created.
That sounds a bit crude, and I don't think it's quite right either. But, nevertheless, the signal arriving at the speaker binding post continues through the binding post down the internal wiring to the crossover. As I understand it, the low, mid, and high, frequencies are filtered and processed by the crossover and proceed to the respective drivers. So what's the point of having another long set of cables from the amp to the second set of binding posts on the speakers, when ostensibly just joining the two sets of posts by jumpers is serving the same function. In other words the signal starts at the amp, is carried to the upper binding posts on the speaker, and via the jumper to the lower binding posts. As far as I recall, because of the hydrostatic nature of electricity, there will be no diminution of current or signal at either set of binding posts. In each case the signal continues through the binding post via the internal wiring to the (in the case of the VR5s) two separate crossover boards, where its filtered (at 3khz and 300khz). I suppose what I am saying is that it seems to me that what happens at the amp end if two sets of cables per speaker are used, is the same as what happens at the speaker end, if jumpers are used: it just takes place at the end of the cable run instead of the beginning.
I've looked at the two suggested sites, but they don't, as far as my maths allows me to determine, address this question. Dielectric parameters etc should be virtually the same using jumpers because of their very short length and the fact they are in essance a continuation of the main cable.
If I had sets of identical cables and jumpers, I would experiement with great vigour! Unfortunately I don't, and here in the UK it's difficult enoough to find dealers willing to let you demo cables without a committment to buy one or another, let alone borrow them for this sort of thing.