I ended up agreeing with the Joseph Weisberg PT book that the most important thing is to get out of the chair frequently for breaks to stretch and/or walk. Furthermore, I found that using break reminder software that blanks out my screen is way more effective than just trying to remember myself or using ordinary timers.

The improvement I experienced beat any chair I ever tried. I felt results on the first day.

Not the answer you were looking for perhaps, but I thought it important to mention.