Clue #2 update - using option #3 (with the "bonus" HST's)
Finished cutting all my rectangles and squares. Finished marking the backs of all the squares.
Last night I decided to make a few test blocks through to completion (I had previously made just 1/2 of the block as a test). I wanted to make sure my points match in the middle. Before I joined the two together I measured the half of the block (one rectangle with two triangles attached) and I noticed that each rectangle had a smidge extra length on one edge of each side. (ie the top right and the bottom left were each longer than the top left and the bottom right). I'm getting a little bit of 'stretch' when I join each triangle to the rectangle.
I'm OK if I trim that smidge off before I join the two blocks - I'm getting a good match of the points in the middle and a perfect 4.5" finished block. But do I REALLY want to trim each of those things? I'm going to make more tests tonight and see if I can figure out a way to avoid that little bit of stretch that I'm getting from joining the triangle.
Hmmm ... maybe my walking foot would help. Will check that out.