It doesn't make any sense for the body to instantly get stronger after merging with a soul. That's never happened in any other story, usually there's a stage of developing the body first, using some special knowledge or tricks.
What? Martin literally just told him that he was giving him a stronger formation that was connected to his mind.
Kyon didn't know that Martin had connected the formation directly to himself, not the device. But it didn't change the accuracy of his dislocation anyway.