Explaining red ink and the phrase "Code compliance failed" to the client is not a path i like to follow. Yor primary purpose as a stress engineer is to ensure the design is as per 'the' code, in a language the client can understand. I can assure you, Project managers can become hysterical at the very mention of non compliance.

which is why i would not readily use ASME B 31.3 clause 319.4.1 (No formal analysis required)
unless i had the original calculations and could prove the two systems were identical.

Guily until proven innocent comes to mind.