There are composite structures out there already, the damage by lightening would not come as a surprise. Alu cage sounds a good Idea.
Anyone remember (from the RAF) community the first pair of GR5s in service and the resulting wing delamination caused as one of them was struck by lightening as they flew in close formation for a photo shoot. - The Lightening struck one then flashed to the other causing 2 u/s A/C!!