I would venture that to do so would devolve into a full source audit, which seriously increases the scope of the test. Full source audits are likely to consume

I would venture that to do so would devolve into a full source audit, which seriously increases the scope of the test. Full source audits are likely to consume ten times or more calendar effort. Performing a full source audit is going to result in sticker shock for all but the most well-funded.