I wouldn't stress out about the 1/4 inch. Consistency usually is good enough for most blocks. Granted some patterns, it matters but many it doesn't. If seams are consistent, it doesn't matter if the block ends up 8 1/8 instead of 8 1/2. The quilt turns out so close to the same. My bee does a friend block once a month. Someone's name is drawn and they choose a block to be made for next time. The blocks are never the same size. Different eyes, different people, different machines.