I bought a Gokhale chair in May 2018, tried it a couple of times for about one hour each time, and found it so painful on my butt (specifically, my coccyx) that it's just been sitting here in my office ever since. I've recently started having a similar problem even with my Aeron chair, and have taken to putting a feather pillow on the seat to provide more cushioning. I use a little rubber ball to roll in the area of the piriformis, and I take frequent breaks, but as a writer I need to be able to sit comfortably. The feeling I'm getting is as if the coccyx is bruised, but I've had no falls or accidents, and as I noted above, there is relief when I use roller balls on either side of the tail bone.
It occurred to me that perhaps you all have some experience with this and can offer helpful suggestions. I'd love to be able to use the Gokhale chair without feeling like my derriere is being flattened like a pancake.
P.S. I've also tried a foam stress wedge—https://smile.amazon.com/gp/product/B000Y9YGFC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1—which also caused terrible pain in the same area. Do I just have a bony tail bone?