The jets can be registered somewhere else (Bermuda, Cayman Islands, Aruba, Isle of Man) and thus never officially imported into the USA.

e.g. https://www.occrp.org/en/investigation/tax-rules-for-the-sup...

No. I live in a wealthy Wyoming town. We already have runners who will bring tax-free construction materials in from Canada and Mexico (or hell, in undeclared cargo, idk) for cash. This is how life works in high-tax states like Greece and India.

I’ve heard private jets goers barely get bothered with customs - I’m curious how much smuggling starts happening via them.