User blog comment:KnocknickKnock/Lucy Stardress:Crux Form/@comment-7418318-20150520191748/@comment-7418318-20150520203025

That's your assumption, but there is no proof in either direction.

But even if it is as you say, it'd still be useless for battle. Crux needs several minutes of sitting still to access any piece of knowledge. How is that going to help Lucy in the heat of battle, where sitting still even for a few seconds can mean certain death?

And there's no need to use it outside of battle, since she could just ask Crux to search for the stuff himself and then tell her.

The only merit this might have is for learning spells, but if it was that easy then Lucy would have done so during the 1-year-timeskip already. She is quite smart after all and wouldn't let such a possibility slip by her if it existed.