One thing I do not get is that it claims you only plug into the
Crank sensor
Throttle position sensor
O2 Sensors
You can effect the timing with the crank sensor, affect the throttle opening by the TPS and effect the fuel only in closed loop operation with the O2 sensors. So this device is limited to those items. Since HD does not use the closed loop range the same for all models the results would be different based on what base calibration is in the bike your working with.
Funny why they don't just pick up the signals at the ECM connector like the PC does rather than make these other connections.

Crank sensor can also be used to determine rpm (I don't believe this device makes timing adjustments). The O
2 sensors actually produce a signal even in open loop mode, the ECM just ignores it. Perhaps this device uses that signal to adjust the open loop AFR? I would have thought you would need a wideband system for that, but then when you read the specs for the Terry version you find that they only adjust AFR to 13.5 for power mode versus 14.7 for cruise (closed loop). And all tuning devices read the throttle position, so that connection makes sense (except it's strange to make the connection at the sensor rather than the ECM connector).
From the scarce information available, it appears that these things are street legal and CARB approved devices that only affect open loop operation. I can't imagine spending any significant amount on such a limited device when you can buy a fully functional device for a similar price. Take a look at the description of a Terminal Velocity 3 on the Terry Components web site, and then look at the price.
Best advice, stick with the major tuning devices and get the bike tuned in all operating modes.
Jerry