Thanks for the mind map, Mark! And yes, I too would like to know what you mean by layers.
I am a relative noob to the Octatrack myself - started using it seriously just this fall, with the goal of replicating some of Anders Bergdahl’s looping tricks. I’ve made good progress there, but there’s so much more to learn. I don’t think prospective owners should consider this as a negative - another way to look at it is, it will be a long time before you get bored from running out of tricks to do with this machine.