If it were so then Concorde could not have been certificated to fly with the heatshield up
Vision was not impeded unduly with the nose raised on Concorde. It's not a heatshield, but for aerodynamic streamlining primarily, though it did protect the windshield from high temperatures that airflow stagnation would have caused otherwise. With the nose down the turbulence was such that the noise generated makes speech difficult to hear.
https://www.flightglobal.com/pdfarch...0-%201503.html
Suggested FAA cockpit vision standards.
The manufacturing industry, represented by the Transport Airworthiness Requirements Committee of the Aerospace Industries Association, maintained that the proposed size of the clear vision field was in excess of that required to meet the most important objective of the proposed standards. That objective was to provide optimum vision for avoidance of midair collisions in "see and be seen" conditions of flight.
https://www.faa.gov/documentlibrary/...c_25_773-1.pdf
More importantly FAR 91.113 (b), which says: “When weather conditions permit,
regardless of whether an operation is conducted under instrument flight rules or visual flight rules, vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft.”