In this photo the knot has moved aft and is small enough to pass round the turning block but the stopper slides on the guy between the twing and the aft block and doesn't interfere with anything. This only works because I am using tapered sheets with 1/8" Spectra. If you use regular sheets the knot would be much bigger and the block would also have to be much bigger. The knot has to pass round the block when the guy becomes the sheet on the other tack.