I took the class with Amanda, and the blanks did spread a bit, but as Mary Kay said, it wasn't a full fuse so they didn't just spread as much as a full fuse.
That said, since I took the class, I've made a lot (around 40) of these using all 3 ring sizes Bullseye sells. I came back from the class and adjusted the schedule to just doing a tack fuse at 1350 for 5 minutes, with a good bubble squeeze (ramp @ 50 degrees/hour from 1100 to 1250, with a 1 hour hold at 1250). And I double the anneal hold time at 900 degrees. This pretty much eliminates the spread and the bubbles and I haven't had any problems, and I have done some very tall drops (19-20 inches).
One final note is that if you just do the tack fuse, you need the square to be a tad bigger, since the edges won't bulge out. I add about 3/8 inch to 1/2 inch for short drops (10 inches or less) and something more for taller drops. Make sure the square fits the drop ring without significantly (more than 1/8 inch or so) hanging over the edges. Otherwise, cut those edges before you fuse (unless you have a tile saw or grinder to take care of the overhang after the fact).