Saving a list without converting

You can use a ScriptableObject, read the Documentation

1) You need to create a class that inherits from ScriptableObject not MonoBehaviour.

 using UnityEngine;
 using System.Collections.Generic;
 
 [System.Serializable]
 public class Values : ScriptableObject {
 
     public List<Transform> blocks;
     
 }

2) Then you need to create an instance of this class to create your own ScriptableObject, which should be done using Editor scripting, for example you can create a special menu to instantiate that object.

Create a new folder called "Editor" and create a class file inside that folder, the class should be something like this :

 using UnityEngine;
 using UnityEditor;

 public class GeneralEditorClass  {
   
     // Use this for initialization
 
     [MenuItem("Create/ScriptableObject")] //this will create a new menu item that will call the "createObject()" method.
     static void createScriptableObject () {
         Values v = ScriptableObject.CreateInstance<Values>(); // this method will create an instance of your ScriptableObject class
         AssetDatabase.CreateAsset (v, "Assets/MainValues.asset"); // create your asset in this location  "Assets/MainValues.asset"
         AssetDatabase.SaveAssets (); // save the asset
     }
 }

Now when you click the "ScriptableObject" item of the "Create" menu , a new scriptable object will show up in your "Assets" folder.

3) Using the ScriptableObject to save data in your script is easy, just create a public object of the "Values" class, and assign your Scriptable object to it, then what ever you do to that list will be saved.

 public Values values;
 
 values.blocks= new List<Transform>();