My guess, based on your quote, is that the butt clamp, (the side thigh bolsters of the seat base) becomes somewhat uncomfortable on the outer thighs after a prolonged excursion. Agree?
I drove the white coupe again today, and noticed that the thigh bolsters definitely make their presence "felt". I did not notice this two days ago, as I was distracted with other observations. I wonder if this will become an annoyance? Of course, that will be a very subjective conclusion over time.