I'm not sure if its the same in Canada but when I went through the process for Australia it depended on where you started the process. I started the process while outside the country so to activate my visa I had to leave and come back but if I had filed while in the country I could have stayed.

I do remember Canada telling my partner she wouldn't be guaranteed reentry while they were processing her PR visa until it was finalised if we left the country though so we just ended up doing the Australian half first and I never went back.