You might try to frame each square with a neutral color, sewing from the back of the block to follow close enough to just miss your points. Then, when all the squares are framed, measure and trim to the same size. then, you either have a
double sash between all the blocks, or you can sash with a whole different color. I think the tiny size difference between each of the blocks with points will not really be noticed that way, but all your points will show.

My sister and I did that quilt and we live 3 hrs. from one another. When I received her star blocks my LC blocks did not size the same. So I remade all the LC blocks and some of the logs had to be trimmed down. Some of the logs in the blocks were a different size. We won a blue ribbon on that quilt and the judge was very complimentary. So it was worth my time to redo those blocks even if some of the logs were of a different size.

I understand the quilt is for your personal use and the on;y advice I have to offer is to frame the blocks. I wish you luck on your decision. It is a pretty quilt when all assembled.

My personal favorite for summer batting is 100% bamboo. It is silky soft, does not beard and is very light weight, but still gives more loft than flannel (besides, you do not need to preshrink it).

I would see if I could get by with a more narrow seam allowance so you didn't lose your points rather than trim them all down. No one will see the uneven seam allowances as they will be on the inside. If they are quite narrow then double stitch or stitch with a smaller stitch. Nothing says you have to have perfect 1/4" seams on the back. It's the front you see.