As I recall, in the old days a pre inspection was mandated by the FAA. Then the rules changed - not so now. One issue not mentioned so far is insurance. When I finished my first project in 1998, Avenco would write first flight insurance if you had a pre-cover inspection by an EAA tech counselor. Not sure the policies now, but It seems to me that in the real world, the insurance companies have sort of become defacto enforcers of the FARs.