Before the offer is relied on for immigration preparation and before work starts. If the commercial expectations change during hiring, update the factual account and obtain review. A previously suitable design description cannot simply be reused for a materially different position. Fix a decision point rather than a date. The split should be settled whenever someone must rely on it: when counsel drafts, when the letter is signed, and again if commercial expectations move during hiring. Each of those is a checkpoint at which the written account either still matches the job or does not, and reusing a stale description is what turns a fixable drafting issue into a credibility problem.
Include prototype deadlines in the lawful-start plan
List any pre-launch prototypes, client demonstrations and preparation tasks expected before the formal start. Identify their locations. Confirm the relevant permission before performing them rather than treating the product launch as the only date that matters.
Ask also who pays for the pre-start work and through which entity. Unpaid preparation is still work, and routing a payment through a Canadian company for tasks performed in the United States does not remove the need for permission. Where a demonstration or client meeting must happen before the formal start, record the country it occurs in and the status relied on for it.
Settling that in advance costs less than explaining afterwards why activity preceded the authorization meant to cover it.