I press to one side, just how I started and it's now second nature.
My one concern about open seams is: if you're machine SID, because the needle moves faster than hand stitching, could it possibly "nick" the seam thread and weaken it and possibly cause that seam to come undone? Whereas with hand quilting that rocking motion would/could move that same thread to the side of the needle. Just a thought......
if one nests those side ironed seams at joining, or "fans" them open at multiple crossings, there's no more bulk than open seams. When sewing points, it's so easy to find the X and aim right for it! JMHO