Chapter 18 of the Pert M Heru
One correction in your statements: “The three realms are physical (waking), astral (duat) and casual (unconscious). The casual realm causes the experiences in the physical and astral realm.”
Note the use of the term “casual” this should be “causal”. Casual is of course regular clothing, hanging out with friends not doing much, sitting around, relaxing, kicking back and “vegging out” watching TV and the like or casually doing ones duties at any given time one pleases or wearing regular clothes around the house, etc. etc..
The term causal is used because this realm of the personality is from where the impetus arises to either create a life of wisdom and enlightenment or a life of ignorance and hardship. Indeed this also relates to the source of aryu that impels and compels one to varied ethical or unethical actions in life and their respective results. So the “causal plane” causes things to come into being. Chapter 18 of the Pert M Heru is a study of the Causal Plane and this was presented at the 2012 Neterian Conference and in the Book Of the Dead.
Indeed, living by truth, that is, by Maat is a key to attaining enlightenment; it means living in such a way so as to 1-discover truth [and there are higher levels of truth as one advances just as there are higher levels of mathematics in college versus elementary school] and then it is necessary to adopt that higher truth (when it is learned) and leave the lower truth behind. Most people have trouble with #2 as they become complacent and comfortable in their convenient adoption of a comfortable #1 that appeals to the ego. If there is no movement to #3 then there will be stagnation and eventually the “kick in the butt” that comes from death which eventually takes away all bodies but by then it is too late. Before death there are adversities through life and if that is understood as a call to move towards truth then adversity turns into prosperity and enlightenment!