If leather conditioners never make it past the top coating, then how do you explain this seat still feeling supple and conditioned 3 weeks later as it sits in my buddies garage? It looks and feels just like the day I conditioned it with D180.
And if it never makes it past the top coat, then how does the leather seat ever get to feel soft and supple, the way it does after applying leather conditioner?
I can't explain what you are feeling, but I can tell you I have never experienced a difference in the "suppleness" of any leather after applying leather conditioner. There is a plastic coating on modern day leather so all the "conditioner" is doing is providing some UV protection and possibly making it easier to clean in the future.
If you were to feel the seats in my Mother's 2014 Cruz with 130,000 miles you would think I condition them all the time. When in reality, I have only done it once or twice. They are super soft and supple. The only thing I do is clean them semi-regularly with APC diluted 10:1 and that's it. I do use an interior detail spray once in a while, but I mean once every couple of months.
Certain leather just feels nice and others don't. The leather in my 2016 Miata don't feel very soft. It's just the kind of leather Mazda used in these vehicles. That SS seat is probably the same leather used in my Mother's car and that could be why it feels so soft. I bet if you never condition the seat again it will still feel soft.