Uniform quadratic product defect for the normalized Dickman kernel

Let $\rho=\rho_5$ be the finite method-of-steps Dickman function, $U=9/2$, and $F(x)=\rho(U-x)/\rho(U)$. There exists a real constant $C>0$ such that

The bound is uniform up to both coordinate boundaries. It controls the normalized Dickman covariance kernel by a quadratic product weight, as required in the covariance-operator estimates.