My take on a simple Player Spawn System

UOP1_Project/Assets/Prefabs/SpawnSystem.prefab

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UOP1_Project/Assets/Scripts/SpawnSystem.cs

+using System;
+using System.Linq;
+using UnityEditor.PackageManager;
+using UnityEngine;
+using UnityEngine.Events;
+
+[Serializable]
+public class PlayerSpawnEvent : UnityEvent<Transform> { }
+
+public class SpawnSystem : MonoBehaviour
+{
+    private static int requestedSpawnIndex = -1;
+
+    [Header("Settings")]
+    [SerializeField] private int defaultSpawnIndex = 0;
+
+    [Header("Project References")]
+#pragma warning disable 649
+    [SerializeField] private Protagonist playerPrefab;
+#pragma warning restore 649
+
+    [Header("Scene References")]
+    [SerializeField] private InputReader inputReader;
+    [SerializeField] private Transform gameplayCamera;
+    [SerializeField] private Transform[] spawnLocations;
+
+    [Header("Events")]
+    public PlayerSpawnEvent onPlayerSpawnEvent;
+
+    void Awake()
+    {
+        try
+        {
+            Spawn();
+        }
+        catch (Exception e)
+        {
+            Debug.LogError($"[SpawnSystem] Failed to spawn player. {e.Message}");
+        }
+    }
+
+    void Reset()
+    {
+        AutoFill();
+    }
+
+    [ContextMenu("Attempt Auto Fill")]
+    private void AutoFill()
+    {
+        if (inputReader == null)
+            inputReader = FindObjectOfType<InputReader>();
+
+        if (gameplayCamera == null)
+            gameplayCamera = GameObject.FindGameObjectWithTag("MainCamera")?.transform;
+
+        if (spawnLocations == null || spawnLocations.Length == 0)
+            spawnLocations = transform.GetComponentsInChildren<Transform>(true)
+                                .Where(t => t != this.transform)
+                                .ToArray();
+    }
+
+    private void Spawn()
+    {
+        int spawnIndex = requestedSpawnIndex < 0 ? defaultSpawnIndex : requestedSpawnIndex;
+        var spawnLocation = GetSpawnLocation(spawnIndex, spawnLocations);
+        var playerInstance = InstantiatePlayer(playerPrefab, spawnLocation, inputReader, gameplayCamera);
+        requestedSpawnIndex = -1;
+
+        onPlayerSpawnEvent.Invoke(playerInstance.transform);
+    }
+
+    private static Transform GetSpawnLocation(int index, Transform[] spawnLocations)
+    {
+        if (spawnLocations == null || spawnLocations.Length == 0)
+            throw new Exception("No spawn locations set.");
+
+        index = Mathf.Clamp(index, 0, spawnLocations.Length - 1);
+        return spawnLocations[index];
+    }
+
+    private static Protagonist InstantiatePlayer(Protagonist playerPrefab, Transform spawnLocation, InputReader inputReader, Transform gameplayCamera)
+    {
+        if (playerPrefab == null)
+            throw new Exception("Player Prefab can't be null.");
+
+        bool originalState = playerPrefab.enabled;
+        // Prevents playerInstance's Protagonist.OnEnable from running before we set the inputReader and gameplayCamera references
+        playerPrefab.enabled = false;
+        var playerInstance = Instantiate(playerPrefab, spawnLocation.position, spawnLocation.rotation);
+        playerPrefab.enabled = originalState;
+
+        playerInstance.inputReader = inputReader;
+        playerInstance.gameplayCamera = gameplayCamera;
+        // Since the prefab's script was disabled it need to be enabled here
+        playerInstance.enabled = true;
+        return playerInstance;
+    }
+
+    public static void SetRequestSpawnIndex(int spawnIndex)
+    {
+        // Prevent setting negative numbers from external sources
+        requestedSpawnIndex = Mathf.Max(spawnIndex, 0);
+    }
+}