How to be sure when the model is fully instantiated in scene?

[massimilianogaio]

HI. I currently use the default GLTFast.GltfAsset script attached to a gameObject to load models into the scene.
In order to access the instantiated model meshes, I wait for GltfAssetBase.IsDone == true. Using this control though, the object is not yet instantiated in scene and I still can't access the created gameObject. So I have to add also a yield return new WaitForEndOfFrame();
This is the code:

protected IEnumerator LoadModelAsync(string uri)
{
    var gltf = gameObject.GetComponent<GLTFast.GltfAsset>();
    gltf.Url = uri;
    yield return (new WaitUntil (() => gltf.IsDone));
    yield return new WaitForEndOfFrame();

    OnImportFinished(transform.GetChild(0).gameObject);
}

For most models, this works. But if the model to be imported has many children (>>200), it is not instantiated in that single frame. So the the code above doesn't work anymore because transform.GetChild(0) is not null but the children are not in the scene yet.
My question is: is there a better approach to determine when the model is instantiated in scene? Thank you.

[WoodsFiend]

You should go async instead of IEnumerator

    private async Task<bool> DownloadModelAsync(string uri)
    {
        var didLoad = await gltf.Load(uri);
        var childCount = transform.childCount;
        
        //This handles the case of already having some children before loading model
        if (childCount > initialChildCount)
        {
            GameObject modelRoot = transform.GetChild(childCount).gameObject;
            OnImportFinished(modelRoot);
        }
        return didLoad;
    }

[massimilianogaio]

Thank you. Yes, I figured out to use the await function few weeks ago.