when i started quilting i came from garment making. i automatically opened every seam. since the seams are stitched on top of by machine, i think they're strong enough not to ravel even if they should by some chance pop. my clothing seams don't pop and they get a lot more movement so why would my quilt seams pop?
i don't like the way corners bunch up when i press to one side, even if you twist the corners (what's that all about?). i had black and blue thumbs from twisting a 100 x 100 quilt and it was no flatter than opening the seams. it fact, you end up with exactly the same number of thicknesses.