Well, first: do whatever is comfortable; if any change makes you feel any kind of discomfort, ignore my advice. :-)
But second: yeah, I find that regardless of the chair type (standard office chair, saddle chair, high stool, or standing with no chair at all) the most comfortable keyboard position is such that my elbows are at about a 90° angle or slightly more, my wrists are as straight as possible, and my upper arms are roughly straight at my sides. In such position, the keyboard has a slight negative tilt.