what does CVarTranslucencyAutoBeforeDOF do?

Our translucent VFX sometimes get blurred by DOF even its pass is After DOF,so i searched code and found this CVarTranslucencyAutoBeforeDOF.It seems that translucent mesh will force render before DOF with this CVar default value.It put mesh behind focus distance into before DOF pass,but not very reasonable.Because dof is not simply background blurring.Now I turned off this function.But I wonder did I misunderstand what TranslucencyAutoBeforeDOF do or this is a poor function?