Allow player to slide off of platform,

I have a FPS Player in Unity that I want to make slide. I came up with this solution for sliding the player off of slopes when they crouch. Slide() is called in Update().

 [Range(1f, 20f)] public float slideSpeed = 8f;
     private Vector3 hitPointNormal;
     private float slideVelocity = 1f;
 
     // Used to tell if we can / are forced to slide
     private bool isSliding
     {
         get
         {
             // If we are crouching and touching the ground
             if (isCrouching)
             {
                 if (isGrounded)
                 {
                     // Then we check if the ground is not flat, but angled
                     RaycastHit hit;
                     if (Physics.Raycast(groundCheck.position, Vector3.down, out hit, groundDistance, groundLayer) || slideVelocity > 1)
                     {
                         hitPointNormal = hit.normal;
                         return Vector3.Angle(hitPointNormal, Vector3.up) != 0;
                     }
                 }
             }
 
             return false;
         }
     }
     private bool wasSliding;
 
     // Method used for sliding
     private void Slide()
     {
         // If we are allowed and/or forced to slide
         if (isSliding)
         {
             // Increase our slide velocity over time
             if (wasSliding)
             {
                 slideVelocity += 0.1f;
             }
 
             // Move the player accordingly
             Vector3 move = new Vector3(hitPointNormal.x, -hitPointNormal.y, hitPointNormal.z) * slideSpeed * slideVelocity;
             controller.Move(move * Time.deltaTime);
 
             // Confirm we were sliding this frame
             wasSliding = true;
         }
         // If we are not supposed to slide, reset everything
         else
         {
             slideVelocity = 0f;
             wasSliding = false;
         }
     }

The way that this solution is set up, the player will abruptly stop sliding as soon as they get to the end of a sloped platform (A floating slope). I want to allow the player to continue off of the platform with their slideVelocity. Any ideas would help greatly. Thanks :),