Noah became more aware of his mental instabilities as he continued to interact with his companions. His pride, greed, and hunger would flare at times and force him to concentrate on suppressing their effects. His friends didn't take those rash behaviors to heart, but Noah felt worried that his new mental energy could hurt them by mistake due to the new power that it had acquired.
The lack of solutions to the issue forced Noah to do his best to keep his emotions and instincts in check. It wasn't anything new for him since he had already experienced a temporary lack of complete control in the past. It was a bit harder to handle now due to the insane level reached by his mind, but he knew that only experience could get him used to his new power.
The partial reveal about Noah's approach to the ninth rank gave a broader vision of the path toward the peak to his companions, but it didn't change how they intended to reach the breakthrough.