I understand, but disagree. I think that when it comes to measuring it is important to be accurate, both for psychological and productive reasons.
As far as mine, I dont cut it, but I add exactly 1/8" to the total. However, I need to find a ruler without the extra bit, because I need to VISUALLY see that 1/8". This is especially important if you are in between sizes.
For example, lets say your NBPL is 7 1/16".. but you use that ruler and all you see is 6 15/16" ( or 7" or 6 7/8"), but you get the point its the difference between being over 7" or being just 6-something. Even though you can add that 1/8", its important to see it.