Again, IRS Pub 463 says otherwise, and within Chp. 2 of Pub 463 it's very specific about workers who are covered under USDOT Hours Of Service Rules. Also TT refers to pub 463 for reference at least 4 different times when I click on "Learn More" tabs within TT.
IRS Pub 463: 2022 Publication 463 (irs.gov)
Individuals subject to “hours of service”
limits. You can deduct a higher percentage of
your meal expenses while traveling away from
your tax home if the meals take place during or
incident to any period subject to the Department
of Transportation's “hours of service” limits. The
percentage is 80%.
Individuals subject to the Department of
Transportation's “hours of service” limits include
the following persons.
• Certain air transportation workers (such as
pilots, crew, dispatchers, mechanics, and
control tower operators) who are under
Federal Aviation Administration regulations.
• Interstate truck operators and bus drivers
who are under Department of Transportation regulations.
• Certain railroad employees (such as engineers, conductors, train crews, dispatchers, and control operations personnel) who
are under Federal Railroad Administration
regulations.
• Certain merchant mariners who are under
Coast Guard regulations.
