If someone comes in as a designated arrival, they could be subject to the enhanced detention without review for up to a year. However, if they are deemed to be a bona fide claimant by the IRB, they could be released as soon as they get protected status, or earlier, upon the discretion of the minister.
But once they get protected status, they would not be eligible to file an application for permanent residency and subsequently sponsor family members for a period of five years. That's to send a message that if you want to come to Canada, don't pay a smuggler.