I know I can do var = component.ie_arc_furnace.getElectrode(3).damage to get the damage of the 3rd electrode, but every time I use that in a lua script, I get this error:

Here's my lua script, the lines prefixed with "--" are commented out, I didn't have an IDE on my test world :P

It's crashing when you try to access "component", indicating that "component" is null. That doesn't appear to be an error stemming from IE.
But I also didn't write this integration, so I can't say more on it.
Plus, 1.12 is no longer being supported.