I don't expect that the CBSA would have a whole lot of influence in whether or not the minister for foreign affairs would put a package forward for GIC consideration to impose sanctions. Our role would be to respond to the sanctions that have been imposed on a person, based on their name, date of birth and other biographical details. Our officials would rely on that biographical information to render an inadmissibility determination.
What options are available to immigration officials, perhaps in response to inadmissibility determination? At ports of entry, CBSA officers—and, in Canada, IRCC officers—have discretion to issue temporary resident permits that will authorize temporary residence to people notwithstanding inadmissibility, including an inadmissibility due to sanctions. This is a regular authority that is at the discretion of officers. We use it every day, I can say.
However, I don't see a role for the CBSA in determining whether or not to impose sanctions on a person or assessing the merits of that decision.