Comment by Majromax

> Even if it is common (i don't think this is required any more anyways), just why?

As far as Canadian law goes, there are two factors at play in the parent's events;

* NAFTA work permits are applied for at the border, on entry; they operate differently from the 'normal' work permit streams.

* Permanent residence is conferred at the border, but the application process can happen either inside or outside the country depending on the stream. There are also limited 'inland' options which evidently have expanded (https://www.canada.ca/en/immigration-refugees-citizenship/se...) in recent years.

In neither case does Canada have a blanket rule that an applicant must leave the country during the whole of an extended application process, and even 'abroad' processes can often be carried out while an applicant is living in the country on other status. (It can get awkward if a consular interview is required, though.)

Unlike the US, Canada is generally comfortable with 'dual intent', where intent to apply for permanent residence through legal channels is not disqualifying for other sorts of statuses.