when i made my silk quilt i did not even think about pressing the seams open instead of to the side---so mine were pressed to the side- for matching intersections- i would think it is totally up to you= if you like it better with the seams pressed open by all means do so--- with the silks in my quilt you can tell (after quilted/bound and washed/dried) that the seams were pressed that way-it is obvious...but i don't think it detracts from the quilt---and anyone not a quilter would have no idea---i can tell because i look. and i believe if you press them open you will be able to look at the finished quilt and see that they were pressed open- just like i can tell they are too the side.
it's up to you===no quilt police to tell you it's wrong- nothing is wrong==just different.