A couple facts: Each side of the controller can handle up to 32 channels Additional channels can be added to network via placing additional controllers adjacent to current controller (with a few structure rules) Dense lines from each side must be completely independent of another, or else the network interferes i.e. 64 channels, when dense lines interfere will be reduced to effectively 32 channel Because of this mechanic, the fact that additional controllers must touch, and their additional dense lines may NOT touch, else interference... How do you suppose it is best to optimize your controllers? Eventually the ones in the middle of your controller multi-block will no longer have available sides to attach a dense line to. Is the 7x7x7 restriction just design oversight, or is there a purposeful reason for this? i.e. Did they just say the max is 7x7x7, or did they have something in mind with 7x7x7 specifically. Is it totally arbitrary?