diff --git a/MCPForUnity/Editor/Helpers/CodexConfigHelper.cs b/MCPForUnity/Editor/Helpers/CodexConfigHelper.cs
index 10f2bacb3..a68d47ed7 100644
--- a/MCPForUnity/Editor/Helpers/CodexConfigHelper.cs
+++ b/MCPForUnity/Editor/Helpers/CodexConfigHelper.cs
@@ -48,16 +48,16 @@ public static string BuildCodexServerBlock(string uvPath)
             else
             {
                 // Stdio mode: Use command and args
-                var (uvxPath, fromUrl, packageName) = AssetPathUtility.GetUvxCommandParts();
+                var (uvxPath, _, packageName) = AssetPathUtility.GetUvxCommandParts();
 
                 unityMCP["command"] = uvxPath;
 
                 var args = new TomlArray();
                 AddDevModeArgs(args);
-                if (!string.IsNullOrEmpty(fromUrl))
+                // Use centralized helper for beta server / prerelease args
+                foreach (var arg in AssetPathUtility.GetBetaServerFromArgsList())
                 {
-                    args.Add(new TomlString { Value = "--from" });
-                    args.Add(new TomlString { Value = fromUrl });
+                    args.Add(new TomlString { Value = arg });
                 }
                 args.Add(new TomlString { Value = packageName });
                 args.Add(new TomlString { Value = "--transport" });
@@ -73,6 +73,9 @@ public static string BuildCodexServerBlock(string uvPath)
                     envTable["SystemRoot"] = new TomlString { Value = platformService.GetSystemRoot() };
                     unityMCP["env"] = envTable;
                 }
+
+                // Allow extra time for uvx to download packages on first run
+                unityMCP["startup_timeout_sec"] = new TomlInteger { Value = 60 };
             }
 
             mcpServers["unityMCP"] = unityMCP;
@@ -197,16 +200,16 @@ private static TomlTable CreateUnityMcpTable(string uvPath)
             else
             {
                 // Stdio mode: Use command and args
-                var (uvxPath, fromUrl, packageName) = AssetPathUtility.GetUvxCommandParts();
+                var (uvxPath, _, packageName) = AssetPathUtility.GetUvxCommandParts();
 
                 unityMCP["command"] = new TomlString { Value = uvxPath };
 
                 var argsArray = new TomlArray();
                 AddDevModeArgs(argsArray);
-                if (!string.IsNullOrEmpty(fromUrl))
+                // Use centralized helper for beta server / prerelease args
+                foreach (var arg in AssetPathUtility.GetBetaServerFromArgsList())
                 {
-                    argsArray.Add(new TomlString { Value = "--from" });
-                    argsArray.Add(new TomlString { Value = fromUrl });
+                    argsArray.Add(new TomlString { Value = arg });
                 }
                 argsArray.Add(new TomlString { Value = packageName });
                 argsArray.Add(new TomlString { Value = "--transport" });
@@ -221,6 +224,9 @@ private static TomlTable CreateUnityMcpTable(string uvPath)
                     envTable["SystemRoot"] = new TomlString { Value = platformService.GetSystemRoot() };
                     unityMCP["env"] = envTable;
                 }
+
+                // Allow extra time for uvx to download packages on first run
+                unityMCP["startup_timeout_sec"] = new TomlInteger { Value = 60 };
             }
 
             return unityMCP;
diff --git a/MCPForUnity/Editor/Helpers/ConfigJsonBuilder.cs b/MCPForUnity/Editor/Helpers/ConfigJsonBuilder.cs
index a81aaf6a9..1e40ba971 100644
--- a/MCPForUnity/Editor/Helpers/ConfigJsonBuilder.cs
+++ b/MCPForUnity/Editor/Helpers/ConfigJsonBuilder.cs
@@ -1,8 +1,6 @@
 using System;
 using System.Collections.Generic;
-using System.IO;
 using System.Linq;
-using MCPForUnity.Editor.Clients.Configurators;
 using MCPForUnity.Editor.Constants;
 using MCPForUnity.Editor.Services;
 using MCPForUnity.Editor.Models;
@@ -90,20 +88,8 @@ private static void PopulateUnityNode(JObject unity, string uvPath, McpClient cl
 
                 var toolArgs = BuildUvxArgs(fromUrl, packageName);
 
-                if (ShouldUseWindowsCmdShim(client))
-                {
-                    unity["command"] = ResolveCmdPath();
-
-                    var cmdArgs = new List<string> { "/c", uvxPath };
-                    cmdArgs.AddRange(toolArgs);
-
-                    unity["args"] = JArray.FromObject(cmdArgs.ToArray());
-                }
-                else
-                {
-                    unity["command"] = uvxPath;
-                    unity["args"] = JArray.FromObject(toolArgs.ToArray());
-                }
+                unity["command"] = uvxPath;
+                unity["args"] = JArray.FromObject(toolArgs.ToArray());
 
                 // Remove url/serverUrl if they exist from previous config
                 if (unity["url"] != null) unity.Remove("url");
@@ -184,27 +170,5 @@ private static IList<string> BuildUvxArgs(string fromUrl, string packageName)
             return args;
         }
 
-        private static bool ShouldUseWindowsCmdShim(McpClient client)
-        {
-            if (client == null)
-            {
-                return false;
-            }
-
-            return Application.platform == RuntimePlatform.WindowsEditor &&
-                   string.Equals(client.name, ClaudeDesktopConfigurator.ClientName, StringComparison.OrdinalIgnoreCase);
-        }
-
-        private static string ResolveCmdPath()
-        {
-            var comSpec = Environment.GetEnvironmentVariable("ComSpec");
-            if (!string.IsNullOrEmpty(comSpec) && File.Exists(comSpec))
-            {
-                return comSpec;
-            }
-
-            string system32Cmd = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.System), "cmd.exe");
-            return File.Exists(system32Cmd) ? system32Cmd : "cmd.exe";
-        }
     }
 }