The CTA said Dorje Shugden is an evil spirit, why don't they ask oracles to take trance of all the enlightened Dharma protector such as Setrap or Palden Lhamo to ask if that is true? If the CTA has strong faith in Nechung's advice, they must be very receptive to other Dharma protectors' advice too. Don't just rely on Nechung because the prophecies he makes most of the time are not accurate. Besides, Nechung is not enlightened.
Setrap is an emanation of Buddha Amitabha and he is one of the Dharma protectors propitiated by the Gelug monks, he has a long history with the Gelugpa, CTA can rely on him for sure. Why is CTA not asking Setrap? Or if not Setrap, why not Palden Lhamo? If Dorje Shugden is so evil and he has to be gotten rid of, CTA should try all divine method.
Tibetan Buddhism is famous for the rituals, especially those or exorcism. Why doesn't CTA gather all the high lama of different lineage and have a series of exorcism rituals to subdue Dorje Shugden? If Dorje Shugden is an evil spirit, the exorcism rituals definitely can help to get rid of Dorje Shugden and then, there will be peace. Why is the CTA not doing that?