This is exactly why I don't like the idea of trimming blocks. I REALLY don't want to sound like the quilt police, but if you measure accurately and sew your 1/4" accurately, you won't need to trim. I've just never figured out why anyone would cut bigger to cut it off and waste fabric and time. Plus, as you know, you run the risk of distorting the original design of the block. Just my opinion of course, but I've never understood the concept.