I haven't done a new autotune yet. I did move my wall mount sensor up to 1" from the top, too. During the seasoning run, it held temp good, so your comment about the AT numbers being significantly different kind of surprises me! That's why I did the seasoning without a new AT; I wanted to see how the old numbers worked with the new element. I'll let you know what the new AT does.
So far, I'm very impressed with the bigger element!