This has been driving me crazy so finally this morning I pulled out some strips and started playing. I made some four-patches using 1.5 inch strips, then took a couple 3" squares, cut them on the diagonal, and used them to make the square in a square. Pressed carefully and then trimmed down the block to 3.5 inches unfinished. Does that accomplish what you are wanting to do? (I am so making this quilt!)