On my 16 1500, I can't get a drastic side to side temp difference. I can on my 18 Pacifica though.
I have tried it more on cooling vs. heat though to be honest.
As far as the seats, the leather does not get as hot as the cloth. Several years ago in the Jeeps at least they had several melt the seat - I do not know if any caught fire - so it is very possible they don't run them as hot as before.
I agree though, you would think there is some spec range that the seats should be at per setting. Esp. since temp by feel is subjective, hot to me might still feel cool to you.