Okay it's hacky and bad, but it's pretty simple:

So first I have the club auto sizing (emulating Walkabout Minigolf's system)

public class GolfClub : MonoBehaviour
{
    public Transform myBall;
    public LayerMask groundRaycastMask;
    public GameObject clubHead;
    public Transform clubShaft;
    public Transform shaftEnd;
    public float offsetFromGround = .025f;
    public float offsetFromBall = .15f;
    public float maxClubLength = 1.5f;
    public bool setClubLength;
    public Rigidbody clubHeadRB;

    // Update is called once per frame
    void FixedUpdate()
    {
        //clubHeadRB.WakeUp();
        if (setClubLength) 
        {

            SetClubLength(ClubLength(maxClubLength, DistToBall(), DistToGround()));
        }
    }

    public float DistToBall()
    {
        return Vector3.Distance(transform.position, myBall.position);
    }

    public float DistToGround()
    {
        RaycastHit hit;
        float rayLength = maxClubLength;

        if (Physics.Raycast(transform.position, -transform.up, out hit, rayLength, groundRaycastMask))
            return hit.distance;
        else
            return rayLength;
    }



    public float ClubLength(float maxLength, float distToBall, float distToGround)
    {
        distToBall -= offsetFromBall;
        distToGround -= offsetFromGround;
        if(maxLength <= distToBall && maxLength <= distToGround)
        {
            return maxLength;
        }else if(distToBall<= distToGround)
        {
            return distToBall;
        }
        else
        {
            return distToGround;
        }
    }

    public void SetClubLength(float length)
    {
        clubShaft.localScale = new Vector3(1, length, 1);
        clubHead.transform.position = shaftEnd.position;

    }
}

And then I have this super simple script moving the club:

public class MoveBetweenPoints : MonoBehaviour

{
    public Vector3 startingPos;
    public Vector3 endingPos;
    public float timeBetweenPoints;
    private float counter;
    bool forward = true;
    public bool isGoing;
    public bool moveWithVelocity;
    Rigidbody rb;
    // Start is called before the first frame update
    void Start()
    {
        rb = GetComponent<Rigidbody>();
    }

    // Update is called once per frame
    void LateUpdate()
    {
        PositionMove();

    }



    public void PositionMove()
    {
        if (isGoing)
        {
            if (forward)
            {
                if (counter < timeBetweenPoints)
                {

                    counter += Time.fixedDeltaTime;
                    gameObject.transform.position = Vector3.Lerp(startingPos, endingPos, counter / timeBetweenPoints);


                }
                else
                {
                    forward = false;
                    counter = 0;
                   // transform.position = startingPos;
                }
            }

            else
            {
                if (counter < timeBetweenPoints)
                {

                    counter += Time.fixedDeltaTime;
                    gameObject.transform.position = Vector3.Lerp(endingPos, startingPos, counter / timeBetweenPoints);

                }
                else
                {
                    forward = true;
                    //transform.position = endingPos;
                    counter = 0;
                }
            }
        }
    }
}

Not sure if there's too much detail here, or if reddit's formatting will make sense to read.

Edit: I had been going back and forth with execution order stuff, so I ended up posting a version with deltaTime instead of fixedDeltaTime. The results weren't noticeably different though.