I am Canadian in USA working and am on a TN valid until June 2026. My son is on a TD until April 2025 due to an expiring passport. I recently got him a new passport . We recently submitted I-140 and will likely hear back around Dec. Should I submit I-539 now for him or wait until closer to his TD expires. My thinking is I should now, because with an approved I-140 they may give us a hard time extending his TD. Thoughts?