TNOUnique.cs

// Editor script to do the same task as if you manually clicked "Assign Unique ID" on all TNObjects

using System.Reflection;
using TNet;
using UnityEditor;
using UnityEngine;

public static class TNOUnique
{
    [MenuItem ("Tools/Assign UniqueId All TNObjects")]
    static void ApplyAllUnique()
    {
        var mStaticIDField = typeof(TNObject).GetField("mStaticID", BindingFlags.Instance | BindingFlags.NonPublic);
        var tnObjects = GameObject.FindObjectsOfType<TNObject>();

        Undo.RecordObjects(tnObjects, "Assign UniqueId All TNObjects");

        int count = 0;
        foreach (var tno in tnObjects)
        {
            if ((int) mStaticIDField.GetValue(tno) == 0)
            {
                var uniqueId = (int)TNObject.GetUniqueID(false);
                mStaticIDField.SetValue(tno, uniqueId);
                count++;
            }
        }
        Debug.Log($"Updated static id on {count} TNObjects");
    }
}