There's only one installer, and that's the only one you should be downloading and running.
What happens if you run the jar manually from a console window?
What you just typed doesn't make much sense in English, and none of it negates the fact that comparing the item that gets picked up to Items.POTATO is more efficient than comparing the registry name.
Why are you chaining getItem()? Nevermind, I didn't realize the number of layers the item itself is wrapped in
and that is not how you check reference equality.