The focus should not be on the 1/4 inch, scant or not. The focus should be on the patch size that is left after seaming and pressing.
Measure the block after seaming left and right edges. Is it correct size? If not, take "scant" smaller or larger seam, whatever is necessary. The size of the seam is relative; the size of the finished patch is not.
This, of course, is from my prospective of reading, and not actually doing. Still working on my first quilt ;-) ;-)