Propilot23K
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I don't know about Denver as such a good choice...
The big freight carriers in USA have traditional selection of Ohio, or Indiana locations as "economic centerpoint" of the manufacturer's production statistics in USA.
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For Europe, I would consider Oostende, or Liège-Bierset as best points, with consideration for Maastricht and Luxembourg.
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Africa would be Lagos, (for West Africa) or Nairobi (for East Africa)... Sharjah is best in the Middle East. Asia, could be Kuala Lumpur. Central America is Panama. In South America, would be Campinas, Curitiba or Porto Alegre, yet in Brasil, always mention Manaus, as hub, in a tax free zone...
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Happy contrails