bkay- I use Bloc Locs for squaring up HST's and it works like a charm. Very good investment.
I would press the seams open.

Gay, thanks for showing me that "square" . I had identified 2 different "squares". This will be much easier.

bkay

I believe I have made this quilt at least 5 times, always pressed to the dark with no problem. MSQC has a similar pattern and I believe the one you’re making. I say that because one of the ones I made I did using Jenny’s method of sewing around the square and cutting on the diagonal. Very fast and easy quilt to make especially when you are using 6.5” HST, makes a big block.