Beautiful! Could you keep it simple and stitch a box around the text? And then maybe some outline quilting in each block. It would be different for each block. I can see 1/4inch quilting line on the inside of the pinwheel block and a diamond outline on the block above and right of that. A diamond outline would work in a number of the others too. You might have to start and stop alot, but that way it wouldn't cover up important details or run over thick seams.