One point perhaps not mentioned is that when installing a different saddle, I have found some saddles to have a large height difference requiring a lowering or raising of the seatpost. If the saddle is too high, like it is with 90% of riders, the torso will not be stable when pedaling. This lack of stability will be felt eventually in the deeper tissues at the sit bones.
I had not solved my derriere pain issues and went for a fit. It isn't clear yet whether it helped. She moved my saddle about 2 cm all the way forward and put me into a 150 mm stem. Says my bike is too small. Seems I am merely more forward onto my hands now with maybe an additional 10 mm reach to the bars. Just mentioning fit as a possibility to improve the butt pain. My stem is now -6 instead of up 6 degrees, too. These changes make a difference on how I sit and how it feels; I just don't have enough long rides to know if successful.