Well, it's in the title.
Obviously, residual and residual(norm) would be different values, but what about deviations within those categories?
Some say that getting all residuals match is near-impossible on a home computer with background processes ( https://amp.reddit.com/r/overclocking/comments/igj1fv/linpack_extreme_residuals_have_to_be_the_same/ ), so settling up with 47-48 matching out of 50 is OK if the test was completed successfully, and achieving full match is only plausible with extremely loose settings, sometimes below factory settings. Is there any reason to strive for all matching residuals?
Well I guess I sorta(?) answered my own question.
Seems like all match to my eye, unless I missed one accidentally. That is WITHOUT hwmonitor running in the background. When it was running I got 3 mismatch residual out of 25. All I did was rebooting the PC. So basically yeah, if you ran at least 50 passes and they finish successfully without errors, the occasional 2-3 residual mismatches are probably caused by background processes minding their own business.
Also I've noticed that multithreading actually lowers my GFlops down to around 330-340, and (unproven, can't testify) supposedly greatly increases your chances for residual mismatch.