Dear Dharma friends, i do not understand how one can come to say that Keith Dowman "… has not published any original translations for many years." He had been very productive in the last years and provided the serious practitioner with many invaluable translations, some translations he might have done as the first one, other had been also translated before. It is not at all unusual to add once own translation when a text had been translated before, this happens a lot and is also very good. Every translator will have his own expertise and will have to add his specific understanding of the text which is very understandable especially with the deep and often very complex texts about Dzogchen. And yes, Mr. Dowman uses new terms, his own way of using terms developed quiet a lot during the many years of his translators career. Unfortunately there is no systematic of technical Buddhist terms in general and with dzogchen terms in particular in the western world. A process of defining such terms has not been yet found place in the western world, as it was quiet different in Tibet when Buddhism came there, and terms have been rendered quiet accurate (nevertheless sometimes quiet different to the respective Sanskrit term) as you can see when you read Tony Duffs book.
So Mr. Dowman brings his suggestion for using terms, which someone may like and someone not, and often he explains his usage of words. he tries to render the terms so they are more graspable in our world and one may have get to get used to it. How ever does that say anything about the quality of his translation. You should read them carefully and maybe compare it with other exosting translation to form a good opinion. Basing opinion on prejudice might not be good, as other people read it then as if " he [is] revising/updating the translations of others, or simply republishing them wholesale" which i would consider as completely false.
Look at his many translations which had been published in the last years, works from Longchenpa and Vairocana:
Eye of the Storm, Vairotsana's Five Original Transmissions
Maya Yoga: Longchenpa's Finding Comfort and Ease in Enchantment
Natural Perfection: Longchenpa's Radical Dzogchen
Spaciousness: The Radical Dzogchen of the Vajra Heart, Longchenpa's Precious Treasury of the Dharmadhatu
and also :
Great Secret of Mind: Special Instructions on the Nonduality of Dzogchen
By: Tulku Pema Rigtsal, translated by Keith Dowman
Yes i agree, it would be helpful the terminology would be more clear, and we could find a standard. How ever we may not be so far and have to look into that. I always wanted to make an online database were such terms could be explained and the different translations could be opposed. It might be helpful for the student to get a deeper understanding what is meant, how ever, it would be a lot of work, and finally only ones own direct insight and sitting experience will finally help with the understanding.
As a last word, also look at Herbert von Günther who also did his very unique translation using his very own terms, made an invaluable contribution for all of us.
Enjoy your fortune to came across such tremendous wonderful teachings, and be happy.