AW.: quartertones and complexity

I've just read through an article by Mahnkopf on Ferneyhough's _String
Trio_(1995). According to Mahnkopf, the pitch content of the piece is derived
from a fixed-register set as follows:

(d = 1/4tone flat, + = 1/4tone sharp, middle C = C4)

C# 7
Bd 6
E+6
E6
Ad5
G5
Gd5
F+5
F5
Ed5
Dd5
B+4
B4
G#4
D#4
C4
G4

An inversion of the same set, beginning on C+2 also figure in the composition.

I've spent some time trying to parse these pitches for any underlying
patterns with little success. Mahnkopf stresses the abundance of 1/4 tones,
tritones, Major sevenths and minor ninths, but their distribution might as
well be random to my ears. Am I missing something? Or, is this just a set of
pitches whose complexity is directly proportional to the size of the set
itself?

Daniel Wolf