Thinking through this, I thought of a possible way to do this. So the add-on would use the Gravity Pull equation to determine how far the wire would "drop" over how far... for people that have actually taken algebra, it's a simple parabola. Now using the equation it would complete the connection between the two bricks by creating either multiple particles, or models, going the whole way .
So, basically;

It would use this model.

Then use that to create something like this as the wire.
Now, if I actually knew how to script, I could give it a shot. But, I don't know how to script for Blockland.