Like mike, you seem to lose symmetry with bigger cubes. Is this also to support your memorization system?
Yes, I think so. Images memorized into a journey for me are completely linear, and I have a hard time "breaking" into a visual journey at a location that is not the very first image of the very first location. Sometimes I vaguely memorize the first image of a location, but I imagine it related to the last image of the previous location in some obvious way. For example if Darth Vader is the last image of one location, and Luke Skywalker is the first image in the next location, then I would do something like this. Darth Vader completes his interaction with the images in the first location, then he might throw his light saber (spinning and twirling through the air) to hit Luke Skywalker at the start of the next location. In this case I would remember that Darth Vader image very strongly and only think of "son" or "son of" as the start of the next journey location. So if I tried to skip to that Luke Skywalker location, I might remember the 2nd and 3rd images perfectly, but not the first because it is tied to the previous location.
A more detailed example might be
Location 1: An Elephant stomps a giant plane of glass, shattering it, and Darth Vader uses his light Saber to delfect the shards and protect himself. (EFWNDV)
Location 2: Luke Skywalker is the first image. I would remember Darth Vader from the previous location so I would go back to the previous location, and after Darth Vader deflected the shards he would throw his light saber twirling through the air toward the next location. I then vaguely picture a human form and think "son of" to remember that it is Luke. The light saber hits the vague human form and is injured. The body slumps over and hits a giant 6 foot tall cup, which slides across the ground into a straw hut, collapsing it. (LSCUHT).
I rarely have two images from different locations interact in an active way like above. Often if there is a loose connection between the last image of a location and the first image of the next location I will still picture the first image in the second location, but I focus on the relation to the last image of the previous location. I do this moreso than interacting the starting image of the second location with the other two images in that location. I hope that makes sense?
Memorizing using single syllable words (see my 5x5x5 central edges and corners) I memorize simply as a string of sounds. I cannot skip to the middle of this sound stream without first having "heard" the first part. This is why my 5x5x5 memorization is so strange in the middle.
Chris