Quote Originally Posted by Captain Morgan View Post
Kyle's ring subsequently didn't have the yellow weakness, but it also didn't have the AI which came standard package to the rings before and since. So he lacked things like auto-shields or a super computer that would already have that kind of information to reference. It added to his whole "rookie flying by the seat of his pants" vibe.

As such, I'd assume a Lantern of any other era can just say "ring, make Kryptonite" and the ring will reference the Krypnonite file, and that's it.
Yeah, that's one of the reasons Kyle is my favourite GL. I like the idea that he's that bit more self sufficient than the rest of the corps, relying on imagination and willpower more than pulling data through from an AI. Darn GLs these days, the rings fly themselves!