If I relocate the PCV valve line into the air box housing, will I gain engine performance and efficiency?
In a word: No.
You won't gain any performance or efficiency by changing the location of the PCV air inlet line. While I'm not sure exactly what you're trying to do (details are lacking in your question), if this was a way to increase performance or efficiency, everyone would be doing it, including vehicle manufacturers.
On the other hand, if you believe this would work for you, there's no reason to not do what you want to do and check the outcome.
You will keep it from working right.
The PCV flow should go from the valve cover (usually) to an under-vacuum part of the inlet. The valve responds to the vacuum to let in less blow-by gasses during light load (when you should have less blow-by). The air box is not under vacuum so this won't work.
I don't think it "wants" to go there, maybe you think it should for some reason?