I know a a AZ contractor that is performing a plethora of plumbing and never having it inspected. One in particular site is an 11 unit apartment complex that he used pex on all the units and installed new mini splits and did not pull one permit for these repairs. He does have a permit on 1 of the units that burnt some months back and he is using it as a "rider policy". I am of the capacity I know commercial property (more than 4 units "copper" pipe is the national mandate, he used pex. I am about to file formal complaints on 3 properties where permits were skirted by a licensed GC, but does not have a plumbers license.