Can we see pictures of the blocks? Or the pattern?
It the blocks are larger - it is easier to fudge them smaller blocks.
One can do a bit of shrinking and stretching with steam pressing. Not my first choice, but it can help flatten the seams.
For me, having the top lay flat is importantvwnd to 3nd up fairly symmetrical.
also, how much of the design would be affected by trimming?