Create a BoxCollider that surrounds an object and its children

AddColliderAroundChildren

// https://gamedev.stackexchange.com/questions/129116/how-to-create-a-boxcollider-which-surrounds-the-gameobject-and-all-of-his-child
private void AddColliderAroundChildren(GameObject assetModel)
{
	var pos = assetModel.transform.localPosition;
	var rot = assetModel.transform.localRotation;
	var scale = assetModel.transform.localScale;

	// need to clear out transforms while encapsulating bounds
	assetModel.transform.localPosition = Vector3.zero;
	assetModel.transform.localRotation = Quaternion.identity;
	assetModel.transform.localScale = Vector3.one;

	// start with root object's bounds
	var bounds = new Bounds(Vector3.zero, Vector3.zero);
	if (assetModel.transform.TryGetComponent<Renderer>(out var mainRenderer))
	{
		// as mentioned here https://forum.unity.com/threads/what-are-bounds.480975/
		// new Bounds() will include 0,0,0 which you may not want to Encapsulate
		// because the vertices of the mesh may be way off the model's origin
		// so instead start with the first renderer bounds and Encapsulate from there
		bounds = mainRenderer.bounds;
	}

	var descendants = assetModel.GetComponentsInChildren<Transform>();
	foreach (Transform desc in descendants)
	{
		if (desc.TryGetComponent<Renderer>(out var childRenderer))
		{
			// use this trick to see if initialized to renderer bounds yet
			// https://answers.unity.com/questions/724635/how-does-boundsencapsulate-work.html
			if (bounds.extents == Vector3.zero)
				bounds = childRenderer.bounds;
			bounds.Encapsulate(childRenderer.bounds);
		}
	}

	var boxCol = assetModel.AddComponent<BoxCollider>();
	boxCol.center = bounds.center - assetModel.transform.position;
	boxCol.size = bounds.size;

	// restore transforms
	assetModel.transform.localPosition = pos;
	assetModel.transform.localRotation = rot;
	assetModel.transform.localScale = scale;
}

Tried that code but the calculated collider's geometry doesn't fit the encapsulated children when the parent of assetModel has modified position, rotation or scale.