Why does COLMAP set the Ceres solver tolerance value to 0 in the bundle adjustment option?

Hello, I was looking at the COLMAP options and noticed that the function_tolerance, gradient_tolerance, and parameter_tolerance values for the Ceres solver used in the Bundle Adjustment step are all set to zero.

However, the initial values in the link below have a very small value close to 0 (ex. 1e-6, 1e-10). Why is COLMAP set to 0?