This is a common practice for a lot of folks including myself, after trimming the nock end off a little (total amount depends on how much I need to cut off of the opposite) I then use a G5 squaring tool to make sure the end is 100% square with the shaft, this tool is used for truing up the shaft surface for nock bushings, as well as the opposite end for the points, point bushing and truing the edge of the bushing for broadheads.
Remember an arrow with the nock end that is not square is like hitting the cue ball with a little English in the game of pool.
Square results in all forces being equal and the arrow launching straight while oscillating from the energy of the bow
Your question is valid it can help in having a finished arrow in which you can gain a straightness % because you are possibly trimming off an irregularities or flaws do to processing. Can one tell the difference in close up target shooting probably not, longer ranges 40 yards and beyond it could, As far as, for hunting and using full blades it can be real noticeable in relation to how much fletching is used to help correct the frontal steering effect.
Fletching and croaked or bent arrows
Thatís why when using the smaller diameter or thin walled aluminum arrows for the youth / lower poundage bows in the indoor events the more helical you can get the less arrow culling you will do to keep your arrows in the X ring
Short range back yard shooting you should be ok, but there's never anything wrong with trying to improve.
A little long winded I apologize.
The only one that is your competitor is the air between your ears!