What I mean by theatrical is that he.
1) does pretty much for every character a different distinct voice. (And does it very well if I may add, he is able to repeat each voice throughout the 3 books with the same characteristics and nuisances Of each different voice)
2) there is sound affects added during the readings ( horses running, orcs and humans, running, swords clashing, thunder, deeper low ent voices (you would have to hear it to know what i mean). Even when gandalf whistles for shadowfax after meeting aragorn, Gimli, and Legolas in fangorn,) music shire sounds, Rohan music, sounds in Rivendell etc...
you are correct there is not a full cast. but there is so much added extras that make listening so enjoyable.
I'm not sure what you mean by "theatrical" audiobooks. It is not a full-cast dramatization, and Mr. Dragash is definitely adapting Tolkien's book, not the films. But, no, I've never encountered this version before now.
What I do have is:
The Mind's Eye audio dramas of both The Hobbit and The Lord of the Rings that aired on NPR.
The audiobook of The Silmarillion as performed by Martin Shaw.
I once had a copy of the BBC radio drama of The Hobbit, but I long ago donated it to a local public library.
Right now I am listening to the final part of the BBC adaptation of LotR via YouTube to see how they dealt with the Scouring of the Shire.