The ex-Sanyo Eneloop system isn't related to the Panasonic unit of this thread of course, so any information from that may not apply. However, it's suspected that the variable resistance "walk-alongside" throttle of the Panasonic unit isn't related to the pedelec unit, but is created by connection to a logic level output on the mainboard to simulate a "pedals-are-turning" signal. It only operates at minimum power so is not very useful, even as a walk alongside throttle. It was indeed originally created by BikeTec, but now adopted by Panansonic as an option.
The thumb throttle is a 10k potentiometer with only part of the range used, throttle off 1.3k, throttle full on 2.5k, giving a 1.2k operating range.
.