I definitely look for the point on the arrow with the stiffest spine. This probaly relates to the spline of a fishing rod.
Most carbon arrows are wrapped and there is a spot where the layers overlap. Often this is the stiffest side, but not always.
I use a homemade spine tester that really is only good for finding relative spine.
Keep turning the arrows to find the stiffest side, mark it and always put that on the high side. Some people use the float test method for finding the heaviest side which usually relates to the stiffest side.
Of course the final test is to shoot groups. It doesn't matter what side the stiffest spine is unless the arrows shoot together.
I've found that when I group tune arrows that are built this way, it doesn't always work out that the arrows shoot better with the stiffest side oriented the same way. Sometimes an arrow won't shoot with the others no matter what I do it. Sometimes turning the nock to the next fletch works, sometimes not. These go into the pile that I use for blank bale work.