Script inheriting SplineController doesn't work the same as adding component?

[clearleaf]

I'm working on a "2.5D" game where you control a character that moves along a spline. I'm new to this level of development so I'm having trouble finding information in the documentation. I did find a suggestion to create a script that inherits SplineController but it's not working the way I expected. In the inspector, all the controls of the SplineController appear. However they don't seem to apply to the character and the character doesn't snap to the spline the way they did with the component.

Code:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class scrPlayerSpline : FluffyUnderware.Curvy.Controllers.SplineController
{

   // Start is called before the first frame update
   void Start()
   {
       
   }

   // Update is called once per frame
   void Update()
   {
       
   }
}

What am I missing? I've selected a spline for the controller in the inspector.