It is quite unfortunate that the the credibility of the Tagpu Pemavajra is being questioned because of the illogical Dorje Shugden ban. Doubts and aspersions are being cast on the vast wisdom and contributions of the Tagpu Pemavajra which actually is way beyond just in connection with Dorje Shugden. However, efforts to downplay and even discredit Tagpu Pemavajra has led to a sticky situation where it brings to question the integrity of Tibetan Buddhism and even credibility of the Dalai Lama.
To illustrate, both Cittamani Tara and Dorje Shugden practice came through Tagpu Pemavajra. How is it logical to dismiss one practice (Dorje Shugden) as demon worship but still proliferate another practice (Cittamani Tara) which came from the same Tagpu Pemavajra? Especially when such claim of demon worship by Tagpu Pemavajra (through his propitiation of Dorje Shugden) would invalidate any teachings from Tagpu Pemavajra.
So, by saying that Dorje Shugden is a demon and those who propitiate Him would have broken their refuge (and therefore invalidated all their practices), then by the same logic, Tagpu Pemavajra would have also broke his refuge. And on that basis, it follows that the practice of Cittamani Tara transmitted by Tagpu Pemavajra and is practiced to date, would be an invalid practice that does not carry the blessings of Tara at all. Thus, one can’t achieve enlightenment with that practice as the lineage itself was broken when Takpu Pemavajra started practicing Dorje Shugden.
To take things further, if the Cittamani Tara lineage passed by Tagpu Pemavajra to Pabongka Rinpoche is invalid, then all the lineage practices passed by Pabongka Rinpoche to Trijang Rinpoche and from Trijang Rinpoche to all his students including the Dalai Lama are similarly invalid.