I am not sure exactly but they are involved in verification, Biometrics, interviews, and visa issuance etc. Since u r already in Canada so there should not be any major role of secondary office. You should inform IRCC through webform that you are already in Canada and should be considered as "Inlander " not Outlander anymore. This may help you to expedite ur processWhere u are living? Its Sydney NS if u are not living in Australia. BTW which is your primary office?