The duties actually performed decide it, not the job title or the industry. The role needs to read as professional technical writing: authoring and maintaining documentation, working from technical source material, and producing manuals or comparable publications rather than performing engineering, testing or production work.
Test the duty list against the profession, not the title
Titles such as content specialist, documentation engineer or knowledge lead say little on their own. Take the written duty list and mark each item as writing, editing, or something else. If the non-writing share dominates, discuss with counsel whether a different listed profession fits better, or whether the position can be described more accurately without misstating what the employer actually needs done.
A sorting rule helps: for each line of the duty list, name the deliverable. If it is a document the applicant authors or revises, the line belongs in the writing column; if it is a validated fixture, a released batch, a signed test protocol or a configured system, it belongs elsewhere, whatever the line is called. Percentages produced that way carry more weight than adjectives.
Hypothetical example: a sterilization validation engineer is offered a position described as writing validation reports; the reports are real, but they document cycles the same person designs and runs, and that combination is not professional technical writing. Where the duties genuinely sit in engineering, a TN request would turn on whether they fit a profession that appears on the USMCA list, such as Engineer, with that profession's own qualification requirements.