The wording in the online physical presence calculator is unclear when it comes to describing travels that happened before an applicant lived in Canada. The one exception is visits to Canada before landing -- there is a clear way to enter those.
Looking at CIT0407E, the form to use when manually calculating an applicant's physical presence, the fields are much clearer:
Section 1 is used to calculate the eligibility period (establishing the application date and the date 5 years before that).
Section 2 is used to calculate the time period between becoming a PR and applying for citizenship. The chart in this section is to be used for all trips made after becoming a PR (including day trips, which count as 0 days absence, but must be listed).
Section 3 is used to calculate the number of days in Canada as a Temporary Resident (TR) or Protected Person (PP) in the period before the application became a PR. The first chart in this section is to be used for all periods during which one held the status of TR or PP, and the second chart in this section is used to calculate absences from Canada during those periods.
The remainder of the form is where the number of days of physical presence is then calculated (adding the totals of section 2 and 3 together).
So someone who never visited Canada before their landing as PR does not have to list any trips made before that date. This also indicates that the physical presence calculation itself is not used to determine if an applicant requires a PCC.
Similarly, the FAQ for the online physical presence calculator (
https://eservices.cic.gc.ca/rescalc/redir.do?redir=faq) says that "all absences from Canada during your eligibility period, the five (5) years preceding the date of your application, must be declared. Therefore your
absences during your time as a temporary resident or protected person within the eligibility period must be declared as well." (emphasis mine -- this implies that they are not looking for travels that are during a time when one is not a TR, PP, or PR)