Do you happen to have any further info or good to knows on that left hand control swap that sounds super interesting to do.
There really isn't all that much to it. I just unsoldered the wires from the factory control, and soldered them to the exact same locations on the new control.
I suggest you simply put both the new switch and the old switch side by side on your workbench, and look where the wires go.. start with moving 1 wire at a time from the old to the new in the exact locations AND pointing in the same directions, they came from (horn wires to horn button, high low wires to high low switch, turn signals to turn signals.. make sure you get the left to go left and right to go right! may be the hardest part of the whole process, just check with multimeter if you are unsure).
When you run out of wires coming from your factory harness, there will be only 5 wires hanging out of the new switch without a home.. 3 of those wires are for the 4 ways, 2 for the flash to pass. separate the 2 wires from the flash to pass, and tie them in as i say below.. the remaining 3 wires, find the turn signal wires and tie them in to the factory turn signal branches, and flasher wire.
To get 4 ways, Yamaha (from the factory euro switch) just takes the left and right signal wires, merges them behind the switch and sends the flasher signal down both left and right lights simultaneously.
--So inside your switch, 3 wires come in for your turn signals.. 1 wire comes from your signal relay wire, 2 wires feed out to the signal light branches. IF you do the wires one by one, you can use your multimeter to determine which wire is which by simply turning on left or right on the original control and see what wires connect.. the wire that connects to both (left when left signal activated, right when right is activated) is your signal wire.
--In my case, I simply added a jumper wire from each pad of the left/right/off switch over behind the 4 way flasher (there is 3 pads there too) in parallel.
Pressing the 4 way button, in all sense of the word behaves exactly the same as simply clicking left or right, except now the output goes down both branches and not one.
Flash to pass, its even more simple, but exactly the same process.. your hot lead "splits" (think of a Y shape) to one side of both your high beam switch AND your flash to pass switch, and the high beam wire "splits" to the other side (that makes them parallel).
NOTES:
-I did mine all within the control, which is hard mode, you can simply connect the wires for the new additions down the loom a few inches to their respective wires, if you don't mind cutting and splicing into your harness (i don't like cutting harnesses personally).
-The main thing to make sure is that you connect the wires to the correct pads when putting on the control, in my case the color code between the donor control and the factory was identical. if you put the hot wire in the wrong spot then things will either be on when they shouldn't be or off when they shouldn't be... or LOUD IF YOU CONNECT THE HORN WRONG!
Last thing.. don't make it more complicated than it is. take time to think it out, everything on the SuperT harness at the control is simply connecting a loop, there is no black magic trickery in there.
Last last thing. if you have a multimeter, put it on continuity mode and click switches until they behave predictably. flash to pass is a no brainer since its just a momentary switch, you can't muck up the order. 4 way, you just press the switch, and look for the pad that makes continuity with the 2 other pads at the same time, that's the signal lead, the other 2 are your light wires.. doesn't matter which light wires go onto which pad because they both flash anyhow.
edit: @Mods.. feel free to move this or link this to the left control thread as needed, if you feel that is more appropriate