Off season calorie ceiling on a blast - where does more food stop building muscle and just add fat?

Six weeks into an off season blast and the appetite from the EQ is getting out of hand. I know I need to eat to grow but at some point shoveling more calories in has to just be adding gut fat rather than muscle. Curious where people have actually found their personal ceiling, whether you track it by weekly weight gain or just by how you look in the mirror. I've been around 4500 calories at 225lbs and wondering if I'm already past the point where extra food is doing anything useful.

Tracking weekly weight gain is the most underrated tool for keeping an off season honest. Half a pound to a pound per week is growth. Anything above 1.5 consistently is fat, simple as that.

The weekly weight tracking point is the one. Scale jumping 3 pounds in a week is glycogen and water, not tissue. Real growth is boring and slow on the scale. If you are adding more than a pound a week consistently something is getting added that is not muscle.