It’d be nice if you could place, say, an enhanced energy conduit and an ender energy conduit in the same block space.

can you explain a reason for running multiple cables in same block? If its to limit power to certain areas of network then use a capacitor or alternate energy cube to junction the lines.

I wanted to place an enhanced energy conduit and an ender energy conduit in the same block space.

thats what i am trying to understand. why?

Because I have some enhanced conduits and some ender conduits.

so just for looks or you updated your conduits and you dont want to waste the lower tiered leftovers?

I upgraded some of my conduits, but not all of them.