If you found a pattern you like that uses primarily 2 1/2" squares, your other pre-cuts could be sub-cut to those squares. They would be great for half-square-triangles.
I happen to have made a bunch of those today. Mine are for a tree of life center block surrounded by maple leaf blocks. I used the method where you cut 2 1/2" squares, face two squares together, sew 1/4" on both sides of the diagonal center line, cut apart on the diagonal, trim to 2" squares.