I don't doubt at all that this is a fantastic sounding truly world-class IEM. However, I take issue with a couple of the points made in the review, and I hope the OP can either address my concerns and perhaps clarify where possible, or else take it as constructive criticism.
1) Good god, custom IEMs are NOT pretty to look at! They're like plastic hardened snot off a handkerchief. It's amazing something that looks so hideous can produce sound so beautifully. (Maybe I'll feel differently about one molded to my own ear shape--getting my first mold this week--but looking at other people's ear cavity shapes is like looking at other people's anal cavity shapes. Nightmare fuel)
2) I feel the introduction comes off as condescending and preachy, as if single dynamic driver designs are inherently superior to all the rest. I know that's not how the OP actually feels, but only because I kept reading.
OF course the head engineer or whoever "feels there are advantages to this design." Every engineer feels that way too, because there ARE advantages to it! There are also disadvantages. That's why there are different designs!
3) After talking about the different bass holes and how they boost the bass, the OP goes on to claim they are neutral "with no frequency boosted." Objectively speaking, these claims are mutually incompatible. They cannot both be true.
4) Actually I really liked this line in particular: "It has the speed for the death metal, every hoarse shout and growl was…you know, I really need to talk to the guy who recommended that…" Well done there!
All in all I hope I don't come off as too hostile, I have specific criticisms, but my negative feelings don't reach beyond those specific instances. I also appreciated the anecdote about emailing the CMA sound engineer, for example.