My guess is that the company just hires dual citizens to avoid visa issues.
US lets you do personal imports up to US$800 per import without taxes/duties, so they limit it to that.
This isn't related, the company can hire anyone they want to man the trucks. Do it often, and you register with FAST.
> US lets you do personal imports up to US$800 per import without taxes/duties, so they limit it to that.
That only applies to personal good, not things you're bringing for commercial purposes, and there's a minimum away-from-the-country time.
I doubt US is letting them bring truckloads in if what I said about tariffs/taxes/duties is untrue.
https://support.chitchats.com/en/articles/1733099-what-items...
No minimum away-from-country time. That's for Canadians, not USians.