Radius and angle of Vector3.Slerp motion arc

Hello. I want to move my character from one point to another in a given time. Using Vector3.Slerp between two points and then projecting it on the normal between two points works well. But it kinda looks unrealistic because character can reach unrealistic speeds. The problem with lerp is it is always constant speed. I want to mix lerp and slerp but for this but I need to know the properties of the arc slerp creates. Like radius and angle. Any help?