Now the results. Was it all worth it?
The jury is still out.
Before I started on the harness install today, I verified the stator performance. I did not get the throttle locked at 5,000 rpm, but I did manage 4,500 rpm. Voltage was 72 VAC on all three pairs. Resistance readings from each lead to ground were all good, as were continuity checks of each lead.
However ... the battery voltage still only gets to upper 13s, even after running for a bit to compensate for the drain of starting the bike. At idle, it will run about 13.0. If the brake light is on, it's about 12.4. At 3,000 rpm (40 mph in fifth gear), it runs about 13.4 volts. Increase speed to 3,500 rpm (48 mph), it rises to about 13.7. Only after running over 4,000 rpm (55 mph) for a while, does it get to 13.9 volts, and slowly drops when the speed is reduced without using the brake light. Yes, it's actually charging the battery, but it's not the "rock-solid 14.4 volts" that others have bragged about.
In the course of troubleshooting, I checked the output of the r/r by pulling the fuse to check open-circuit voltage. It's about 15.1.

As soon as I plug the fuse back in to connect the r/r to the battery, it's back down to the upper 12s or lower 13s, depending on engine speed. The only thing I could find that increased the voltage was pulling the headlight fuse. When the voltmeter was reading 13.2, I pulled the headlight fuse and saw 14.3 volts, and this was at about 2,000 rpm. This surprised me a bit, as only the headlight and the instrument lights are on that fuse. I have re-wired the tail light and connected it to the terminal strip powered by the relay, as the tail light was flashing a bit when the headlight modulator was in use. Now that it's powered more or less dirrectly off the battery, it does not flicker nearly as much. Also, to eliminate the possibility that the year-old AGM battery is loading down the system too much, I installed a much-newer (3 months) AGM battery from #2 son's bike. Same results.
I am running out of time here, as I need to pack for my next trip, but it's doing well enough for her to ride to work for the next month while I am gone.
Now, was it worth it? Yes. The harness was $40, but included everything you need to install the FET r/r, and it's a nice, tidy installation. It is helpful to have a good set of crimpers for the uninsulated terminals, but you should already have everything else you need for the install. If you only want the two large connectors that plug into the r/r, they are also available from Eastern Beaver for $20. I just decided to go all-out and get the whole harness.
Your mileage may vary.
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