E-3 plugs worth the money?

And no, all those multiple ground wire tricky plugs are a marketing gimmick.

There are times when a different ground wire or center electrode is called for. Two strokes benefit from a very fine center wire, and some four strokes that are ignition deficient will benefit from a very small diameter center wire.

Some engines do well with a cut back ground wire. You have to test.

Outside of those two things, the rest is just blowing sunshine up your skirt.