Security screening is done by external agencies like CBSA/CSIS and I don’t think VO can do anything about due date once they have sent a case to CBSA/CSIS for security screening as these agencies need to work with various security agencies/organizations in different countries based upon a candidate’s travel history.
Now, not everyone goes under security screening. Most people only go through security check, while some people with extensive travel history or travel to some middle eastern countries are known to be picked for security screening.
If you would like to know whether or not you’re under security screening and what’s going on with your case, order CBSA/CSIS notes.