TransformAsList

 public class TransformAsList<T> : IList<T> where T : Component
    {
        private readonly Transform transform;
        public TransformAsList(Transform transform1) => this.transform = transform1;

        public IEnumerator<T> GetEnumerator()
        {
            for (int i = 0; i < transform.childCount; i++)
                if (this[i] != null)
                    yield return this[i];
        }

        IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();

        public virtual void Add(T item) => item.transform.parent = transform;

        public virtual void Clear() { for (int i = 0; i < transform.childCount; i++)  RemoveAt(i); }

        public bool Contains(T item) => transform.GetComponentsInChildren<T>().Contains(item);

        public void CopyTo(T[] array, int arrayIndex) => throw new System.NotImplementedException();

        public virtual bool Remove(T item) => (item.transform.parent = null) == null;

        public int Count => transform.childCount;

        public bool IsReadOnly => false;

        public int IndexOf(T item) => item.transform.GetSiblingIndex();

        public void Insert(int index, T item)
        {
            item.transform.parent = transform;
            item.transform.SetSiblingIndex(index);
        }

        public void RemoveAt(int index) => this[index].transform.parent = null;

        public T this[int index]
        {
            get => transform.GetChild(index).GetComponent<T>();
            set => throw new System.NotImplementedException();
        }
    }