Puedes modificar “EquipamentHandler” para que cuando llame a la funcion “EquipItem” se llame a la funcion “SetActiveHolster” del Script “Holster”, sin tener en cuenta nada mas que colocar “SetActiveHolster” . using System.Collections;
using System.Collections.Generic;
using DevionGames.UIWidgets;
using UnityEngine;

namespace DevionGames.InventorySystem
{
public class EquipmentHandler : MonoBehaviour
{
[SerializeField]
private string m_WindowName = “Equipment”;

[SerializeField]
private ItemDatabase m_Database;
[SerializeField]
private List<EquipmentBone> m_Bones= new List<EquipmentBone>();
public List<EquipmentBone> Bones
{
get { return this.m_Bones; }
set { this.m_Bones = value; }
}

[SerializeField]
private List<VisibleItem> m_VisibleItems= new List<VisibleItem>();
public List<VisibleItem> VisibleItems {
get { return this.m_VisibleItems; }
set { this.m_VisibleItems = value; }
}


private ItemContainer m_EquipmentContainer;

private void Start()
{
this.m_EquipmentContainer = WidgetUtility.Find<ItemContainer>(this.m_WindowName);
if (this.m_EquipmentContainer != null)
{
for (int i = 0; i < this.m_VisibleItems.Count; i++)
{
this.m_VisibleItems[i].enabled = false;
}
this.m_EquipmentContainer.OnAddItem += OnAddItem;
this.m_EquipmentContainer.OnRemoveItem += OnRemoveItem;
UpdateEquipment();
if (InventoryManager.current != null) {
InventoryManager.current.onDataLoaded.AddListener(UpdateEquipment);
}
}
}

private void OnAddItem(Item item, Slot slot)
{
if (item != null && item is EquipmentItem)
{
EquipItem(item as EquipmentItem);
}
}

private void OnRemoveItem(Item item, int amount, Slot slot)
{
if (item != null && item is EquipmentItem)
{
UnEquipItem(item as EquipmentItem);
}
}

public void EquipItem(EquipmentItem item)
{
foreach (ObjectProperty property in item.GetProperties())
{
if (property.SerializedType == typeof(int) || property.SerializedType == typeof(float))
{
float value = System.Convert.ToSingle(property.GetValue());
SendMessage(“AddModifier”, new object[] { property.Name, value, (value <= 1f && value >= -1f) ? 1 : 0, item }, SendMessageOptions.DontRequireReceiver);
}
}

for (int i = 0; i < this.m_VisibleItems.Count; i++) {
VisibleItem visibleItem = this.m_VisibleItems[i];
if (visibleItem.item.Id == item.Id) {
visibleItem.OnItemEquip(item);
return;
}
}

StaticItem staticItem = gameObject.AddComponent<StaticItem>();
staticItem.item = InventoryManager.Database.items.Find(x=>x.Id== item.Id);
VisibleItem.Attachment attachment = new VisibleItem.Attachment();
attachment.prefab = item.EquipPrefab;
attachment.region = item.Region[0];
staticItem.attachments = new VisibleItem.Attachment[1] { attachment};
staticItem.OnItemEquip(item);
}

public void UnEquipItem(EquipmentItem item)
{
foreach (ObjectProperty property in item.GetProperties())
{
if (property.SerializedType == typeof(int) || property.SerializedType == typeof(float))
{
SendMessage(“RemoveModifiersFromSource”, new object[] { property.Name, item }, SendMessageOptions.DontRequireReceiver);
}
}
for (int i = 0; i < this.m_VisibleItems.Count; i++)
{
VisibleItem visibleItem = this.m_VisibleItems[i];
if (visibleItem.item.Id == item.Id)
{
visibleItem.OnItemUnEquip(item);
break;
}
}
}

public void UpdateEquipment()
{
for (int i = 0; i < this.m_VisibleItems.Count; i++)
{
VisibleItem visibleItem = this.m_VisibleItems[i];
visibleItem.OnItemUnEquip(visibleItem.item);
}
EquipmentItem[] containerItems = this.m_EquipmentContainer.GetItems<EquipmentItem>();
foreach (EquipmentItem item in containerItems)
{
EquipItem(item);
}

}

public Transform GetBone(EquipmentRegion region) {
EquipmentBone bone = Bones.Find(x => x.region == region);
if (bone == null || bone.bone == null) {
Debug.LogWarning("Missing Bone Map configuration: “+gameObject.name);
return null;
}
return bone.bone.transform;
}

[System.Serializable]
public class EquipmentBone{
public EquipmentRegion region;
public GameObject bone;
}

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

#if UNITY_EDITOR
using UnityEditorInternal;
using UnityEditor;
#endif

namespace MalbersAnimations.Weapons
{
public class Holsters : MonoBehaviour
{
public HolsterID DefaultHolster;
public List<Holster> holsters = new List<Holster>();
public float HolsterTime = 0.3f;

public Holster ActiveHolster { get; set; }

/// <summary> Used to change to the Next/Previus Holster</summary>
private int ActiveHolsterIndex;

private void Start()
{
for (int i = 0; i < holsters.Count; i++)
{
holsters[i].Index = i;
}

SetActiveHolster(DefaultHolster);
PrepareWeapons();
}

private void PrepareWeapons()
{
foreach (var h in holsters)
h.PrepareWeapon();
}

public void SetActiveHolster(int ID)
{
ActiveHolster = holsters.Find(x => x.GetID == ID);
ActiveHolsterIndex = ActiveHolster != null ? ActiveHolster.Index : 0;
}

public void SetNextHolster()
{
ActiveHolsterIndex = (ActiveHolsterIndex + 1) % holsters.Count;
ActiveHolster = holsters[ActiveHolsterIndex];
}

public void EquipWeapon(GameObject newWeapon)
{
var nextWeapon = newWeapon.GetComponent<MWeapon>();

if (nextWeapon != null)
{
var holster = holsters.Find(x=> x.ID == nextWeapon.HolsterID);

if (holster != null)
{
Debug.Log(holster.ID.name +” "+ holster.Weapon);

if (holster.Weapon != null)
{
if (!holster.Weapon.IsEquiped)
{
holster.Weapon.IsCollectable?.Drop();

if (holster.Weapon)
holster.Weapon = null;
}
else
{
//DO THE WEAPON EQUIPED STUFF
return;
}
}


if (newWeapon.IsPrefab()) newWeapon = Instantiate(newWeapon); //if is a prefab instantiate on the scene

newWeapon.transform.parent = holster.GetSlot(nextWeapon.HolsterSlot); //Parent the weapon to his original holster
newWeapon.transform.SetLocalTransform(nextWeapon.HolsterOffset);

holster.Weapon = nextWeapon;
}
}
}

public void SetPreviousHolster()
{
ActiveHolsterIndex = (ActiveHolsterIndex - 1) % holsters.Count;
ActiveHolster = holsters[ActiveHolsterIndex];
}

//[ContextMenu(“Validate Holster Child Weapons”)]
//internal void ValidateWeaponsChilds()
//{
// foreach (var h in holsters)
// {
// if (h.Weapon == null && h.Transform != null && h.Transform.childCount > 0 )
// {
// h.Weapon = (h.Transform.GetChild(0).GetComponent<MWeapon>()); ;
// }
// }
//}
}  using System.Collections.Generic;
using UnityEngine;

#if UNITY_EDITOR
using UnityEditorInternal;
using UnityEditor;
#endif

namespace MalbersAnimations.Weapons
{
    public class Holsters : MonoBehaviour
    {
        public HolsterID DefaultHolster;
        public List<Holster> holsters = new List<Holster>();
        public float HolsterTime = 0.3f;

        public Holster ActiveHolster { get; set; }

        /// <summary> Used to change to the Next/Previus Holster</summary>
        private int ActiveHolsterIndex;

        private void Start()
        {
            for (int i = 0; i < holsters.Count; i++)
            {
                holsters[i].Index = i;
            }

            SetActiveHolster(DefaultHolster);
            PrepareWeapons();
        }

        private void PrepareWeapons()
        {
            foreach (var h in holsters)
                h.PrepareWeapon();
        }

        public void SetActiveHolster(int ID)
        {
            ActiveHolster = holsters.Find(x => x.GetID == ID);
            ActiveHolsterIndex = ActiveHolster != null ? ActiveHolster.Index : 0;
        }
         
        public void SetNextHolster()
        {
            ActiveHolsterIndex = (ActiveHolsterIndex + 1) % holsters.Count;
            ActiveHolster = holsters[ActiveHolsterIndex];
        }

        public void EquipWeapon(GameObject newWeapon)
        {
            var nextWeapon = newWeapon.GetComponent<MWeapon>();

            if (nextWeapon != null)
            {
                var holster = holsters.Find(x=> x.ID ==  nextWeapon.HolsterID);

                if (holster != null)
                {
                    Debug.Log(holster.ID.name +"   "+ holster.Weapon);

                    if (holster.Weapon != null)
                    {
                        if (!holster.Weapon.IsEquiped)
                        {
                            holster.Weapon.IsCollectable?.Drop();

                            if (holster.Weapon)
                                holster.Weapon = null;
                        }
                        else
                        {
                            //DO THE WEAPON EQUIPED STUFF
                            return;
                        }
                    }


                    if (newWeapon.IsPrefab()) newWeapon = Instantiate(newWeapon);       //if is a prefab instantiate on the scene

                    newWeapon.transform.parent = holster.GetSlot(nextWeapon.HolsterSlot); //Parent the weapon to his original holster          
                    newWeapon.transform.SetLocalTransform(nextWeapon.HolsterOffset);

                    holster.Weapon = nextWeapon;
                }
            }
        }

        public void SetPreviousHolster()
        {
            ActiveHolsterIndex = (ActiveHolsterIndex - 1) % holsters.Count;
            ActiveHolster = holsters[ActiveHolsterIndex];
        }

        //[ContextMenu("Validate Holster Child Weapons")]
        //internal void ValidateWeaponsChilds()
        //{
        //    foreach (var h in holsters)
        //    {
        //        if (h.Weapon == null && h.Transform != null && h.Transform.childCount > 0 )
        //        {
        //            h.Weapon = (h.Transform.GetChild(0).GetComponent<MWeapon>()); ;
        //        }
        //    }
        //}
    }

#region Inspector
#if UNITY_EDITOR
    [CustomEditor(typeof(Holsters))]
    public class HolstersEditor : Editor
    {
        public static GUIStyle StyleBlue => MTools.Style(new Color(0, 0.5f, 1f, 0.3f));
        public static GUIStyle StyleGreen => MTools.Style(new Color(0f, 1f, 0.5f, 0.3f));

        private SerializedProperty holsters, DefaultHolster, /*m_active_Holster, */HolsterTime;
        private ReorderableList holsterReordable;

        private Holsters m;

        private void OnEnable()
        {
            m = (Holsters)target;

            holsters = serializedObject.FindProperty("holsters");
            DefaultHolster = serializedObject.FindProperty("DefaultHolster");
            HolsterTime = serializedObject.FindProperty("HolsterTime");


            holsterReordable = new ReorderableList(serializedObject, holsters, true, true, true, true)
            {
                drawElementCallback = DrawHolsterElement,
                drawHeaderCallback = DrawHolsterHeader
            };
        }

        private void DrawHolsterHeader(Rect rect)
        {
            var IDRect = new Rect(rect);
            IDRect.height = EditorGUIUtility.singleLineHeight;
            IDRect.width *= 0.5f;
            IDRect.x += 18;
            EditorGUI.LabelField(IDRect, "   Holster ID");
            IDRect.x += IDRect.width-10;
            IDRect.width -= 18;
            EditorGUI.LabelField(IDRect, "   Holster Transform ");

           //var buttonRect = new Rect(rect) { x = rect.width - 30, width = 55 , y = rect.y-1, height = EditorGUIUtility.singleLineHeight +3};
            //var oldColor = GUI.backgroundColor;
            //GUI.backgroundColor = new Color(0, 0.5f, 1f, 0.6f);
            //if (GUI.Button(buttonRect,new GUIContent("Weapon","Check for Weapons on the Holsters"), EditorStyles.miniButton))
            //{
            //    m.ValidateWeaponsChilds();
            //}
            //GUI.backgroundColor = oldColor;
        }

        private void DrawHolsterElement(Rect rect, int index, bool isActive, bool isFocused)
        {
            rect.y += 2;

            var holster = holsters.GetArrayElementAtIndex(index);

            var ID = holster.FindPropertyRelative("ID");
            var t = holster.FindPropertyRelative("Transform");

            var IDRect = new Rect(rect);
            IDRect.height = EditorGUIUtility.singleLineHeight;
            IDRect.width *= 0.5f;
            IDRect.x += 18;
            EditorGUI.PropertyField(IDRect, ID, GUIContent.none);
            IDRect.x += IDRect.width;
            IDRect.width -= 18;
            EditorGUI.PropertyField(IDRect, t, GUIContent.none);
        }

        /// <summary> Draws all of the fields for the selected ability. </summary>

        public override void OnInspectorGUI()
        {
            serializedObject.Update();

            EditorGUILayout.BeginVertical(StyleBlue);
            EditorGUILayout.HelpBox("Holster Manager", MessageType.None);
            EditorGUILayout.EndVertical();

            EditorGUILayout.PropertyField(DefaultHolster);
            EditorGUILayout.PropertyField(HolsterTime);
            holsterReordable.DoLayoutList();

            if (holsterReordable.index != -1)
            {
                EditorGUILayout.BeginVertical(EditorStyles.helpBox);
                var element = holsters.GetArrayElementAtIndex(holsterReordable.index);
                var Weapon = element.FindPropertyRelative("Weapon");

                var pre = "";
                var oldColor = GUI.backgroundColor;
                var newColor = oldColor;

                var weaponObj = Weapon.objectReferenceValue as Component;
                if (weaponObj && weaponObj.gameObject != null)
                {
                    if (weaponObj.gameObject.IsPrefab())
                    {
                        newColor = Color.green;
                        pre = "[Prefab]";
                    }
                    else pre = "[in Scene]";
                }


                EditorGUILayout.LabelField("Holster Weapon " + pre, EditorStyles.boldLabel);
                GUI.backgroundColor = newColor;
                EditorGUILayout.PropertyField(Weapon);
                GUI.backgroundColor = oldColor;
                EditorGUILayout.EndVertical();
            }
            serializedObject.ApplyModifiedProperties();
        }
    }
#endif
#endregion
}