It is great to see another application for the Korg Nutube.
I have previously encountered it in Pre'-Amp's of which I am having one built, a Phonostage and DAC.
I see no reason why this new application will fail to find users, especially if the Circuit Design is enabling the Korg to really perform.
The controlling the Nutube's microphonic ring, is going to be a hurdle to get over with only a very compact space to produce control measures.