Self-imported tractors from a brand you know may not have things you expect like PTO safeties and driver seat disconnects.
The same brand and model from a different region is not the same tractor! Core components may be very similar but, they are not the same! They can be stopped at the port of entry because they are not compliant with current USA safety requirements, it isn't just an emissions thing!
Old tractors imported in bulk in a shipping container are a different thing. Importing one new SCUT will likely NOT be cost competitive for most people. Like a non-compliant car made overseas, anything is possible with enough money for USA compliance and verification, or wait for it to age out of the requirements!