i would never throw away a block for being too small- i would set it aside to use somewhere else-
and how important is your 1/4" seam???
you should strive for getting it right- but no one is perfect-
if you are making a 16 patch (checkerboard) square- and your seams are off just a tiny bit (1/8") --you join the first row of 4 squares...1/8" x 4--- you are 1/2" off---if you joined two of these blocks you are a whole inch off- by the time you put 6 blocks together for the first row of blocks your measurements are off by 3 whole inches!!!
those little bits add up-
sometimes it works to cut a little larger and trim down- or use a scant 1/4" but for every 1/8" off you are- every 8 seams will add to a whole inch