SJ,

I too agree with richard. thorough testing (smoke test , regression testing )is required before releasing of any product.As of now , you can check changes or updates in new version of code and convey how it will affect the stress analysis to your client in seperate note. [I worked as release & QA engineer for mechanical product previously. those days usally i did not have sleep continuously for 10 days before release of the product for testing and checking]

regards