@MrQ You can always apply for Exceptional Promise and talk about your experiences, the TN case officer can always endorse your application to either Exceptional Promise or Exceptional Talent.
I have worked in the tech industry for last 13 years as a Software Engineer, Product Manager, Research Engineer, Project Manager and Executive (but at different stages within that 13 years). Though I have worked in the industry for over a decade since, I applied for AI/ML field as a researcher (which I started doing in last 4.5 years only), so, on my endorsement application I have applied for Exceptional Promise. That being said, I provided my experience, contributions and achievements in the tech sector as evidences for a longer period than 4.5 years. Based on the evidences and my story the TN case officer endorsed me as Exceptional Talent.
So, my suggestion is that its better to be humble in the endorsement application but at the same time be confident to talk about your achievements and experiences to show yourself as a Exceptional Talent via the evidences. The TN case officer will decide the rest.
You can read about my endorsement application here: This is how I got my Endorsement for Global Talent Visa under Exceptional Talent Route (AI/ML Researcher)