When I first went through this new inspect/register process, the county tax office could not "see" the inspection record on the computer, though it supposedly updates from the inspection station to the state's computer system the county reads. I had taken the printed inspection report with me, and that was acceptable to the county registrar.
The inspection itself was a joke as far as safety concerns - no check of lights, hitch/safety chains, tires or brakes....And, though the inspection station only collects $7, there is another $7 collected in the registration process, so $14 for someone to verify my trailer VIN.
If it quacks like a tax, it's a tax, not a "fee for service", regardless of the legislators' claims otherwise.