What are the material manifestations of Moon-Ka? The dreamlands?

For a recap of how the astral plane worked in the French, check this post. Anyway, an old French article suggested some ideas I found very interesting. All of the elements besides Moon-Ka have obvious material manifestations: mountains and soil for Earth-Ka, skies and winds for Air-Ka, forest fires and lava flows and lightning storms for Fire-Ka, bodies of water and waterways for Water-Ka... but what of Moon-Ka? That article suggested that the material manifestation is dreams. Solar-Ka is provided by dreamers, the energy of their aspirations and desires, is reflected by the Moon and materializes into Akasha. The astral plane itself fall under the analogy of the Moon. But a lunar materiality is thus false, changing, inconstant: an immaterial materiality. Conversely, the fears and worst desires of humanity are refracted by the residual Black Moon Field and materialize into nightmares.

I'll get into more detail as I start adapting more of the third edition rules to the US version's setting (one of the key changes I'm making is, running with the rules for Shemmut, condensing the summoning worlds and the subtle planes into a single expanse), but this has consequences for the Selenim. Although Major Arcana specifies they can learn Shemmut to a high proficiency, they have incredible difficulty accessing and operating in the higher planes due to the lack of any Black Moon Field. Conversely, they find it easy to access and operate within the lower planes compared to Nephilim, who are penalized by the strengthening Black Moon Field. But by pursuing the Quest for the Bronzen Sublimation, they cultivate their own Solar-Ka and create their own Akasha!