TransformInspector

    using UnityEngine;
    using UnityEditor;
    using System;
    using System.Reflection;
    using Editor = UnityEditor.Editor;

    [CanEditMultipleObjects]
    [CustomEditor(typeof(Transform), true)]
    public class TransformInspector : Editor
    {
        static Type s_InspectorType;
        static MethodInfo s_OnEnableMethod;

        Editor m_InspectorInstance;
        Action m_Inspecotr_OnEnable;

        static TransformInspector()
        {
            var type = typeof(Editor).Assembly.GetType("UnityEditor.TransformInspector");
            s_InspectorType = type;

            s_OnEnableMethod = type.GetMethod("OnEnable", BindingFlags.Public | BindingFlags.Instance);
        }

        void OnEnable()
        {
            m_InspectorInstance = CreateEditor(targets, s_InspectorType);

            m_Inspecotr_OnEnable = (Action)Delegate.CreateDelegate(typeof(Action), m_InspectorInstance, s_OnEnableMethod, true);
            m_Inspecotr_OnEnable?.Invoke();
        }

        void OnDisable()
        {
            if (m_InspectorInstance)
            {
                UnityEngine.Object.DestroyImmediate(m_InspectorInstance);
                m_InspectorInstance = null;
            }
        }

        public override void OnInspectorGUI()
        {
            using (new EditorGUILayout.HorizontalScope())
            {
                using (new EditorGUI.IndentLevelScope(1))
                {
                    using (new EditorGUILayout.VerticalScope())
                    {
                        m_InspectorInstance?.OnInspectorGUI();

                        var indentPerLevel = 15F;
                        var lastRect = GUILayoutUtility.GetLastRect();
                        var singleLineHeight = EditorGUIUtility.singleLineHeight;

                        lastRect = DrawButton(lastRect, EditorGUI.indentLevel * indentPerLevel, 0, singleLineHeight, "S", x => x.localScale = Vector3.one);
                        lastRect = DrawButton(lastRect, EditorGUI.indentLevel * indentPerLevel, singleLineHeight + 2, singleLineHeight, "R", x => x.localEulerAngles = Vector3.zero);
                        lastRect = DrawButton(lastRect, EditorGUI.indentLevel * indentPerLevel, singleLineHeight + 2, singleLineHeight, "P", x => x.localPosition = Vector3.zero);
                    }
                }
            }
        }

        Rect DrawButton(Rect previousRect, float x, float offsetY, float height, string name, Action<Transform> callback)
        {
            var rect = previousRect;
            rect.x = x;
            rect.y -= offsetY;
            rect.width = rect.height = height;
            if (GUI.Button(rect, name))
            {
                Undo.RecordObjects(targets, "Inspector");
                foreach (Transform item in targets)
                {
                    callback(item);
                }
            }

            return rect;
        }
    }