I was using keyframes in Video Pro X14. and while using it, I found a keyframe option called: manual bezier interpolation. It says the bezier handles can be manually interpolated using the arranger. But where is the arranger? I can't find it.
When you activate the keyframe curve(s) by clicking the appropriate eye(s) - indicated by the yellow arrow in the image below below - the effect curve will appear on the object as indicated by the red arrow.
You can then edit the nodes moving them as required to achieve an effect suchas this example: