In my experience in automotive - assembly of front and rear axles, we monitored the application torque in the same way you described, BUT, we would also verify the "Break Away" and "Start Up" torque. This required an electronic torque wrench with force mapping technology. We used a portable datamyte collection system most of the time. Anyway, I am attaching a .jpg of a curve. At point 1, this is the breakaway force. At point 2, it is the start up force. Based on correlation studies of the in-line testing and the torque tests, we found the start up torque was a much better indicator of the application torque. Also, you must test with slow turns to ensure your gage detects the start up force.
With documented correlation studies, you can justify performing the gaging after the application is completed to your customers and auditors, rather than spending the additional costs for in line gaging.