The activity must be assessed on its actual facts before travel. Calling a work activity orientation does not authorize it.
Give the reviewer an activity schedule
Describe whether the visit involves observation, productive tasks, training or customer delivery, and who benefits from the work. Keep the employment start conditional on appropriate authorization. The unresolved duty discrepancy should not be hidden by relabelling the first week as a visit.
A Canadian citizen can apply at a port of entry on the day of travel if the letter and credentials are complete, but the preparation — fixing the duty description, obtaining transcripts and resolving self-employment questions — typically takes several weeks. Build a sequence from the employer's final letter, credential readiness, any licence issue, the intended request or filing method, inspection or adjudication outcome, and the individual's actual admission record. If the employer, duties, or client assignment changes, request a fresh assessment rather than assuming the original plan still applies, and remember that a temporary TN offer does not remove the need to consider longer-term intent. Meetings booked around an assumed start date create pressure to proceed on assumptions, and moving a calendar entry is far easier than undoing an activity already performed.