The wavelength 1.7 cm is invariant with respect to AdS-CFT duality, because it corresponds the wavelength, when the character of energy spreading changes from longitudinal waves to transversal one. From AWT perspective the CMB corresponds the capillary waves at water surface, which are spreading along it by the lowest speed at wavelength of 1.73 cm from exsintric perspective, enabling to interact with as large space-time, as possible and allowing the most advanced evolution of matter inside it. Classical quantum mechanics cannot handle gravity (phenomena) at all and quantum noise blurs in CMB noise above human scale by the same way, like relativity is limited by CMB noise (GZK limit, CMB Doppler anisotropy, etc.) in its predictions.
From cosmological perspective, the wavelength of CMB (1,7 cm) corresponds the outer diameter of Universe or the wavelength of Hawking radiation of tiny black hole, whose lifespan corresponds the age of our Universe generation (13.7 GYrs) - so we can say, the CMB is Hawking radiation of the black hole, which we are living in, i.e. red-shifted radiation of most distant quasars. The foamy character of energy spreading enables to see the event horizons of our Universe both from inside, both from outside via CMB radiation (i.e. the event horizons of most distant quasars observable). The larger (gravitational waves) or shorter waves (gamma radiation) are of limited scope with compare to CMB due the dispersion (GZK limit) in analogy to capillary waves spreading at water surface (compare the celerity curve bellow). The energy density of 3D space-time (roughly given by third power of Planck constant, i.e. 1oE+96 J/m3) corresponds the mass density of black hole, which is forming it.
From AWT follows, every Aether fluctuation of diameter bellow 1.7 cm will dissolve into photons and neutrinos, while the larger objects will collapse into heavier objects and evaporate by the same way. The black holes of diameter bellow 1.7 cm can evaporate via Hawking radiation during observable Universe lifespan, while these larger ones will evaporate by accretion radiation - so we can say, such objects are the most stable objects inside of observable Universe generation and accretion radiation is AdS-CFT dual to Hawking's one (massive objects bellow 1.7 scale falling into event horizon would appear like tiny quantum fluctuations from distant perspective outside of black hole due the immense space-time compactification around it). The density of largest black holes existing inside of observable Universe (with 10+9 times the mass of the sun, which has a radius of event horizon about 109 km) should be comparable with human scale (1 kg per dm3).
Curvature instability is scale invariant. During Big Bang event, all particles were formed by supersymmetric gravitons, the average size of which corresponded the wavelength of CMB photons. During universe evolution the larger gravitons condensed into particles and objects of observable matter, while the smaller fluctuations have evaporated into antiparticles of matter, which were dispersed by its repulsive gravity into clouds of dark matter, surrounding the objects of normal matter. The same criterion can be applied for planet and planetoids formation or even for predators-prey relationship of biosphere. Only pieces larger then some 1.7 cm can serve as a nuclei for accretion and subsequent gravitational growth, or they would become dispersed by radiation pressure of CMB photons. The smaller pieces of matter tends to condense as a whole in large clusters, instead (large means > 1.7 cm).
From AWT follows, the size of photons is given by interference of light wave with graviton background of Planck length scale, forming the quantum foam background of universe. From interference condition follows, the size of wave packet is equal to their wavelength size exactly at the 1.7 cm scale, which effectivelly means, microwave photons are serving both like particles, both like waves, i.e. by the same way, like gravitons in previous generation of Universe, expanded during inflation or like graviton waves in future generation of Universe before its gravitational collapse. The photons of larger wavelength cannot exist, because they tend to condense spontaneously with these smaller ones into solitons of negative rest mass (axions, or so called tachyon condensate).
Even tiny droplets and bubbles in mixtures tends to shrink and evaporate bellow 1.7 cm scale, while larger droplets and bubbles expands and fragments. The least stable droplets of 1,7 cm diameter (liposomes) could started the evolution of life at shallow places of ancient oceans (i.e. inside of multiphase environment of the largest possible complexity). The repeated breakdown by surf waves enabled them to compete for collection and/or (later) production of surfactants, which enabled them to remain as stable, as possible. Whole evolutionary process lasted whole Universe age, because AWT makes no conceptual difference between evolution of inorganic matter and organic life. Therefore it's nothing very strange, the quantum nature and size of neural standing waves corresponds the size of Universe scope, perceivable just by these waves (i.e. quantum gravity standing wave, forming the observable Universe generation). The increasing density of Universe resulting from vacuum foam collapse corresponds the expansion of the scope of human consiusness, capable to comprehend an increasing space-time portion of Aether chaos complexity during time.
The anthropocentric question, whether 1.7 cm distance scale is adjusted by evolution or it just enables the best visibility of Universe remains a tautology by Aether theory, because from AWT follows, every object which is product of less or more long term evolution has tendency to remain adapted to its environment and vice-versa. The scope of observable Universe always depends on entropy density of observer (i.e. number of time events/mutations involved) - the primitive organisms can see their Universe smaller, the more intelligent larger accordingly.
Lord Byron: "Truth is always strange — stranger than fiction."