Wow!! That's a lot of pieces and a lot of bias!! I truly think that things have just stretched a bit here and there. I have a friend who swears by finger pressing (again, not rubbing or stretching) all the pieces in a block. She doesn't iron press until the block is complete.
I would suggest to continue to put the pieces together. Any time one unit is larger than the next, match the intersections, and put the larger piece on the bottom. The feed dogs will help ease in the extra fullness. If the block still looks puffy or out of square after it is completed, you can lay it on the ironing board, measure and pin to proper size, and then spray wet it and let dry. You will be surprised at how the stretched bias edges will revert. Don't give up!!