Not an expert but re. your lovely image of wrapping them in foil, what I understand is that the long power lines pick up the huge surges and it's these that dam

Not an expert but re. your lovely image of wrapping them in foil, what I understand is that the long power lines pick up the huge surges and it's these that damage the transformers. So AFAIUI just disconnecting the transformers would protect them. But I repeat my disclaimer.