Thank you Iceblossom for a great explanation. I always learn something from your posts.
I press to the dark side on most seams. I twirl the intersections if it can be done. Sometimes, I even press a cross seam. One part starts one way and the next one is the other way. So I will do a pressing that changes directions in the half-way point of the seams. That might be naughty but it works for me.
By the way, my LA quilter has quilted my quilts with some seams pressed open. Can you show the person a sample sandwich and why the stitch length needs to be shorter? This seems like a perfect opportunity to communicate and show the reasons why to the quilter.
Good luck!