ok. ideally spatial would just ignore components it didn't recognise but for now try adding this script and running it (it will be in the Tools menu)

csharp
using UnityEngine;
using UnityEditor;

public static class RemoveStrokeMetadata
{
    [MenuItem("Tools/Remove StrokeMetadata")]
    static void Run()
    {
        var all = Object.FindObjectsOfType<StrokeMetadata>(true);
        foreach (var c in all) Object.DestroyImmediate(c, true);
        Debug.Log($"Removed {all.Length} components");
    }
}