Source: TW
I once had correspondence with him (Dyczkowski) about the pashchimAMnAya in the saundaryalaharI. He was a very good scholar.
Apparently, it was Alexis Sanderson who inspired him to turn to the pashchimAMnAya, in whose study his contribution is incalculable. He also had a connection to the learned Gopinath Kaviraj, the brilliant vA~Nga scholar of the mantramArga, via his successor. I have only glanced at parts of his final work – new edition and translation of the tantrAloka of abhinavagupta and its commentary by jayaratha, but it promises to be of great value.
It is unfortunate in his later years he got a bit entangled in the anti-H movement.
His death brings to mind that of the Dutchman Jan Schoterman who died mysteriously just before completing his work on the kubjikA upaniShad.
In terms of contribution to the pashchimAMnAya, he is at the pinnacle along with Goudriaan, Schoterman, Sanderson. Of these Goudriaan was a wideranging scholar and was pro-H until his death in 2016.
Dyczkowski mentions that when he was working with the rAjopAdhyAya in Nepal he had intense experience as though the goddess of the pashchimAmnAya was impelling him from deep within to publish the texts of her tradition. It seems this was true and he lived to see that fructified.
He expired in Kashi as well! A man blessed by Shiva for such a death. That too on Sarasvatī pūjā tithi!