I agree completely with what you're saying and was only trying to say that I think that the lower copper content plus the fact that I had my speaker wire to the tweeter posts caused them to be fatiguing (maybe that's the wrong term? It sounded like the highs were too loud before and aren't any longer).
That could be because of other factors, but most likely it has to do with the stock jumper, although not necessarily because of much lower output from one to the other. For example, different materials and thickness of cables (as well as jumpers) can affect the volume a little bit, but while a decent copper cable can be better than a jumper, I don't think it will have been that audible. What is likely is that there are also room modes in your room, which compounds with the stock jumper; if it was solely the jumper then the factory would have noticed that. What they didn't have and you didn't have was each other's room, which is why one should never ignore it, even on a desktop system.
As for my little experiment, I am only curious to see if I could reduce the gain on the tweeter by plugging my cable into the woofer posts and then using the stock jumper with its lower copper content, since, as you suggested, it seems to have lowered the output of the woofers when i had my cables running to the tweeter terminals with the stock jumper was installed.
In addition, I understand that the only reason the bi-wire is doing me any good is the improved conduction through the wires vs the stock jumper and that I could make a jumper from speaker wire which would be just as good. However, I've already made up speaker wire with the length I want and tinned the ends while I was at my parents house and so, rather than doing more work to make jumpers, I'm going to just leave them bi-wired, at least until I get some banana plugs.
It's not impossible, but the thing is, as much as I'd really much rather cut a section of hte cable and use them as jumpers, if you already have them bi-wired now there's really no point in going back to the stock jumpers or even cutting up the cables for jumpers (unless you can use the extra run elsewhere). What I'm getting at is to either look at where else the system can be improved, or sit back and enjoy listening on them. Getting into this hobby means you know your way around stuff and can set them up properly, and know how to identify issues and deal with them, but still at the core of it is to sit back and listen. If you focus on flaws too much you'll never enjoy your system, and I've seen too many people (more on speakers of course than headphones) get SARS* when the real problem is the room (or the car, and they aren't installing it right and using time alignment).
One last thing - you soldered the speaker cables? You could have protected the strands with a banana plug (that way you only handle it once). I just used bare wire and didn't move them around that much either (at least not that I'd need to remove the cables).
*Severe Audio Replacement Syndrome - unlike the WHO-level SARS, this one is more a danger if one's wife doesn't agree with it, or if the bank has to come and haul it all away. Also known as "upgraditis."