My apologies.
I read the post and saw 8.5" - maybe because that's my go to ruler.
On an 8" ruler, the exact measurement is a bit over ~ 1.6", so going up or down an 1/8" won't matter much at all.
Just FYI - the closer the cut is to the corner of the square, the thinner your wedges will be in the center when you sew the twister-ed(?) blocks together