Pierre - I've thought about asking questions several times about this subject, sometimes in response to comments by you or other inspectors.
To begin: I worked as an independent contractor, doing start up at new coal, gas, wood, oil, ...... power plants. First, the design engineering firm did the design, and in most cases purchased the major components. Because of the time lag from design to actual delivery not all items were as ordered. The drawings were all stamped and approved.
I was contracted to the engineering firm to inspect, correct and calibrate.
Very seldom was a circuit found that did not require changes. I started in the switchyard and worked every circuit and control. The electrical contractor was required to furnish me electricians to make all corrections, do all testing required (and we checked everything), basically they worked with me for the 8 months to a year that start up required. No circuit was allowed to be energized the first time except under my direction, while I checked that all meters, inputs, outputs, voltages, amps, etc.....
I alread stated very seldom was a circuit found that did not require changes. Vendors make mistakes, the design engineers made mistakes, the construction electricians make mistakes - these have to all be found and corrected before you energize.
A few times inspectors did come out to the job - for just a short time, and then left. They actually did not do any inspections. I, and others doing electrical start up did the inspections. A simple example, if wire size was to small, installed per the drawing, we required the EC to remove and install the correct size - yes he was paid, not really his fault that he did not realize the size was incorrect.
You have said you would not approve field changes to approved plans. Maybe the difference between commercial and industrial requires a different view of things. We red lined a master set of drawings which were sent to the engineering firm when we were done - (last day on job).
I guess that perhaps because of my background I cannot understand non acceptance of changes without written permission from the PE who stamped the drawing. Puzzled.......