In this work, we revisit the application of PDFT in the end-grafted PB systems. Firstly, a rigorous derivation of PDFT coupled with the physical constraints of end-grafted PBs is provided. Then, the equilibrium density profiles of neutral and charged end-grafted PBs from MC and MD simulations are introduced to calibrate the PDFT predictions. We find the excellent agreement between PDFT and MC/MD simulations for the neutral and weakly charged PBs, demonstrating the reliability of PDFT. And a little deviation is captured within the cases with strongly charged PBs, which may be due to the difference in model between PDFT and MD simulations and the increasing contribution of ion-ion electrostatic correlations.