My DX3.0 can't make the the throttle dead band wider, only narrower.
But I set the throttle trim pretty high that the motor was engaged and spinning with a good speed. Unfortunately the LED was still flickering which caused the motor to cog (the current was turned off for a very short period of time or may be even a brake was applied). I can't tell if this can be noticed during a normal driving.
I have a different spectrum RX to test it with....