Dromtung Rinpoche dosent need to hide from the CTA as he is operating on grounds that CTA dare not go to: the Chinese. It is a very well known fact that the CTA hate the Chinese to the core, usually opting to forgo Chinese news and updates (of arrested Tibetans, maybe for more sympathy from the public?) and so by targeting the Chinese, Dromtung Rinpoche's Dharma works are not impeded and can spread far and wide because the Chinese couldnt care less about CTA anyways. Most Chinese people dont really care about the Dalai Lama and the CTA as well. A brilliant strategy by Dromtung Rinpoche, I must say.
It is unfortunate that although HH Dromtug Rinpoche is operating in countries which are not under CTA or the Dalai Lama’s jurisdiction, he has to go underground with his Dorje Shugden practice. I believe that this is because the Dalai Lama is internationally recognized as the highest authority in Buddhism, though technically, while his role is as the spiritual leader of Tibet, he is not the spiritual head of any of the Tibetan schools.
In the Gelugpa school, which the Dalai Lama is a member of, the spiritual head is Gaden Tripa, which many people not familiar with Tibetan Buddhism would not know. The other schools have their own spiritual leaders, such as the Karmapa for the Karma Kagyu school (though this school has controversies of their own with the two Karmapas), Sakya Trizin for the Sakya school and so on.
As many people are not aware of this and since the Dalai Lama has publicly condemned Dorje Shugden and banned his practice, people who do not know any better simply accept the Dalai Lama’s edict and blindly follow the ostracisation of Dorje Shugden practice and its practitioners. This is why even great masters with huge temples and bigger sponsors like HH Serkong Tritul and HH Dromtug Rinpoche have had to pretend outwardly that they do not practice Dorje Shugden.
I do not believe that these masters are being duplicitous but merely practical. In order for them to spread the Dharma as they have been doing to many, they had to put their protector practice underground - for now. I hope the ban will be lifted soon so all Dorje Shugden practitioners will be able to ‘come out of the closet’! Then we will really see how pervasive his practice is!