I have started to attack that problem as well, I am currently working with a local shop, but it is now working as well as I hoped. I really need to seek out a new place. The best that I can do for the moment is to tell you to search for a local place that works on motorcycle seats. I want someone who is going to use a multi layers of foam at different densities. Memory foam does not work well, and it holds heat which adds to the problem. Gel pads do not work and they dry up, and crack.
To get the Xciting seat softer they are going to have to shave back some of the foam and build it up properly. Also they are going to need to cut that stupid dome out of the seat pan and replace it with fiberglass or metal. One more thing, you need to make sure that the shop that works on your seats keeps the moister barrier (plastic sheet) in place under the vinyl, or else your seat will really take on water if it is out in the rain as it may take forever and a day to dry out otherwise.
Tom