Are these four add-on wiring techniques all up to code?
Imagine ants climbing up a tree to harvest its fruit. It is a proper "tree topology" - None of the branches ever touch each other.  Ants are allowed to scurry up and down any branch in any order, but cannot leap or fall from branch to branch.

At any point on the tree, if we clamped an "ant current meter" around the branch, it would count exactly as many ants going up the branch as down.  Once past that point, ants might zig-zag up any number of sub-branches, but the ant must come back past this point at the end of the day.  144 ants go up past the point , 144 ants come back.  Ant currents are equal.  If there was a Residual Ant Fault Current Device, it would not trip. 

If any of the branches touched each other, it would be possible for ants to go up branch 1 and come back on branch 2, making ant currents unequal on those branches. 

So a "tree topology" is a pretty strong defense against the unequal currents problem.  How do you detect whether your diagram is a tree?  The "paint bucket" fill tool makes easy work of it. Trees don't enclose areas, so the paint should be able to reach all points (except between wires inside a cable.) 



Nope, in #4, the wires enclose a space, so it's not a tree diagram, and currents are not equal because currents can encircle the space, imbalancing currents in every cable/raceway on each side of the space.