Most Kick down issues are a result of lack of Pedal travel ie the Pedal hits the floor. Just plain old wear and tear. With a Rod system it can be sorted by just pulling the Pedal up to bend it some what.
Better not to use Kick Down, as it usually triggers full throttle,,,, not always needed nor wanted..... I use the gear lever to select a lower Gear and then the Throttle as necessary. If the Engine is in good Tune and the linkage in good order and set correctly then a part throttle downshift can be obtained.
This applies to all Auto Boxes. Holden Trimatics were horrible Cars to drive as the Factory settings held Top gear till the death. A simple change of a Valve Body Spring transformed the driving experience.