It depends on what the person actually does. Where knowledge transfer is part of continuing professional practice within the listed profession, the work may still fit. Where the assignment becomes general training or line supervision outside that profession, the classification question changes.
Test the handover against the profession, not the label
Set the handover tasks beside the duties described when the case was first prepared. Reviewing designs, completing analyses, or closing out professional deliverables while a successor observes reads differently from a period spent running orientation sessions. Counsel can say whether the revised description still matches the listing the case relies on, and whether the employer letter needs rewriting before the dates change.
The actual profession’s requirements and necessary credential evidence still need assessment. Only if the professional agronomy work is the substance of the position and the sales element is incidental. Begin with the proposed duties, the payroll employer, the customer’s role, and the agreement governing supervision. Confirm Canadian or Mexican citizenship, match the day-to-day services to a profession listed under USMCA, and test the credential against that profession’s particular qualification rule. The work also needs to be prearranged professional activity in the United States for a U.S. entity through a U.S. or foreign employer, not self-employment.