I know overlapping, stacking, won't be an addition to the game, but what about a bridge? The bridge, like in the app game Flow, allows energy to be transferred over a set metal or wire without interfering with the wire underneath.
Just use INST. The wiki doesn't explain this but you can actually just build a cross out of INST and it'll behave as if it were two separate wires, a horizontal and a vertical one.
You can also use different kinds of conductors that simply don't conduct electricity to one another. METL, PTCT, NTCT and INWR are four such conductors, none of which conduct to one another.