Ok, here is my followup. Sure enough, 3 of the 4 turn signals were wired with the polarities reversed. It didn't matter for the regular bulbs, but the LEDs definitely cared. I spent about an hour fixing the problem and now all of the LEDs are installed and working.
In addition, I also installed the "extra bright" brake LEDs from the above-mentioned site (I think the same ones Greywolf mentioned in another thread). Boy, what a difference! I'm very happy with the results, so thank you for the tip to the quick fix.
I will be installing the new Admorelighting lite bar next weekend, so look for a post from me in the related thread once that's done.
I tell you guys, between the wired Givi trunk, the LED bulbs and soon the LED lite bar, the back of my Wee looks like a Christmas tree... a very fast Christmas tree
And for the record, Heavy is NOT a prick. You can quote me on that