I don't think it works the same way for the certificates as it does for passports. At the ceremony I was asked if I need to travel any time soon and I said yes, that my flight is in one month, so the agent did a note on my file. Then I let various agents know that I need my certificate asap when a couple of weeks passed and submitted IRCC form inquiry with the ticket attached. They said that the timeline of the certificate arrival cannot be influenced, it is up to my processing office and that they operate at reduced capacity due to the virus
p.s. my trip date already passed 4 days ago, still nothing in mail after almost 6 weeks of waiting