Max didn't know it yet, but his performance was far from average, and it had not gone unnoticed.
Most Battle Cannons can only fire roughly once every second, but a shot every five seconds is standard for the sake of accuracy. The big gun shakes not only the pilot, but the Mecha, requiring pilots to compensate and adjust their targeting if they plan to get the following rounds even close to their intended target.
With Nico having upgraded his Battle Cannon, he could fire twice a second. The multiple targeting feature of his System would constantly update predictions for firing solutions, and while indirect firing Max was unable to tell what was enemy Mecha moving and what was his mecha moving.
Nico took full advantage of the situation as well, having linked to his Mecha's display using her Innate Talent. She overlaid his Targeting information on her own display, showing where incoming rounds would be hitting.