I finally got the HTEV system working. Turns out there was more than one problem with it. First off, the ECU had a bad driver, so there was no power to the HTEV servo motor. Secondly, there was a spread terminal at the ECU plug making poor contact on the +5 VDC HTEV position sensor wire.
It would have been mostly simple to fix, but my first used eBay ECU caused my bike to have no spark. I had to go through the resolution center to get a refund. The second used ECU caused my bike to run on three cylinders. I had to go through the resolution center
again to get a refund on that one. Today I installed used ECU #3 and it works like a charm.
The engine definitely runs smoother under 3000 rpm. The EFI is calibrated to have some exhaust back pressure at low revs, so with my HTEV previously stuck in the 3000-8000 rpm position, the idle was much higher and hunted up and down, and the throttle was jerky under light loads.
It will be interesting to see how the FE is with this bike. I'm not expecting much with 929cc, but hey, you never know - it might be decent.
Here is a video of me testing the HTEV out: