Hi Mik,
I won't mention any of my design, but that the controls are partly responsible for minimizing any digititis the dac/player might present. But even set neutral, digititis has not been mentioned in the reviews, and PMs I have received, as a problem. (Of course TT might be better.)
As you mentioned in your review of the Lessloss, there are designs that seem to minimize or eliminate the problem of digititis.
"Point? The Lessloss 2004 DAC is a mightily ambitious product yet remains coherent and never strays into classic digititis."
"Treble performance is excellent, with shimmer, sparkle and fireworks. However, in my system it did occasionally show elements of hardness that I associate with digititis. How bad? Not bad at all. In fact, upper frequencies are presented exceptionally well. Why bring it up then?"
"Honestly however, treble performance of the Lessloss 2004 DAC is outstanding. Integration with the whole allows a relaxing yet highly resolved portal to the recording. The usual complaints about digital treble are minimized to such a degree that I would be very surprised if anyone shopping in this price bracket would find fault with it."
What might also help mik, even more, is bypassing the analog/mute sections. I can see your concern of older dacs/players though when you stated:
"What I'm saying is that either so-called neutral systems do not recover the rich, organic flow of music, or that this character does not survive digitization and has to be infused at the playback side."
But I think this may be a mute point with the Altmann, Lessloss, other improved designs, or simply bypassing the analog stages in the dac/player.
Hope this helps.