I followed directions like these on how to put together the flying geese for the quilt that I'm in the throes of. It wasn't this specific set of directions, but the whole assembly process is the same.
I will NEVER again use this process.
There is an overlap in the first phase of stitching that creates an incredibly lumpy seam allowance at the point of the big triangle. That lumpy seam allowance is pure torture to sew over accurately. Agony. Painful. Annoying to the Nth degree. Pinning carefully does NOT help.
And only now am I realizing this, as I created all of the pieces before I started sewing them together. And even then, I had to sew lots of them together before I could define the problem.
I've long said that there are prices to be paid for short cuts. Some of them are worth it, some are not.