Lilienthal wrote: "My point is: your product is a mixture of everything soluble in aqueeous MeOH / EtOH and unsoluble in ethanol. That simply means: Polar compounds, e.g. amino acids, peptides, sugars, nucleotides, or urea, just to name a few."
I have just tried to get a precipitate from glucose and of tryptophan in a similar way (shake with 140 proof ethanol, filter off the solids and mix the liquid with 10 times as much 190+ proof ethanol) but didn't get any precipitate.
So Lilienthal is right in general terms. But specifically with cubensis extraction I still think that the white stuff which drops out of the filtered 140 proof ethanol extract at the moment that 190+ proof is added is fairly pure PSOP.