I’m not sure what that .ini is you are referring to, but I can tell you how I have my TQ6+ configured.
Change you throttle axis to the on with with “0 - 100” in its name. Then in the sensitivity settings , configure the point you crossover into reverse with the “Neutral” slider. For me, that is -59%, which rests right on my idle detent. Even without said detent, you can still specify a point on your axis that this occurs.