This will depend from case to case and also from Visa Office to Visa Office. I have seen some cases getting PR in less than 6 months after nomination.
When submitting PR application if PNP nominee you do not need to include the following:
1) Proof of funds (you only need to state what you have)
2) Education Proof (you only need to fill in the form and state, like proof of funds)
3) Proof of connection (sponsor, friend, family does not get mentioned in this application, only if it is direct family like brother, mother, child, etc)
All of these have been checked by CIC and have already been approved. Sending additional documentation will just take more time for the officer assessing your file. It will also then in turn delay the rest of the applicants timelines. You should only submit what asked, nothing more, nothing less.
CIC does however have the right to ask for the above mentioned documentation/proof and may also call you in for an interview, where they can ask you to bring the documentation along.
