[Warning, ESV dragonborn spoiler]
First of all, this inquiry is coming from someone who a month ago thought, "CHIM" was an acronym of some sort.
But this aside, I've been able to collect a considerable amount of information concerning this. Essentially, I know that in order to achieve CHIM, one must understand that he is part of the dream of the Godhead, or Amaranth of this multi-verse, (I say this due to the existence of Oblivion, "here").
We all realize that this must be a literal understanding, else everyone who believes he exists in a dream would suddenly be flooded with knowledge of CHIM. So one who achieves CHIM must fully understand the universe.
Now is my question, how? If you can, "fully comprehend" someone throwing a handful of sand into the air you are on par with modern day RL supercomputers. Certainly the brute force approach will not suffice, I guess it's off to Apocrypha to get busy, but even then, there are things Mora himself, the bloody Prince of Knowledge does not know, as the Skaal were able to keep him away from what ever precious morsel of knowledge they were hoarding.
Therefore, I don't speculate it is too perilous to keep knowledge from him. And if Mora does not know all, no one does, save Anu perhaps if there is any truth within the legends.
Is there something I am lacking in my logic? I have not paid much regard to Vivec's verbose lectures.