Because I'm lazy and didn't want to have to redo T1, I went with the following AC: T1=17, T2 = 18, T3 = 19, and T4 = 20. The results were interesting. I'll try to write up the tables tonight, when I have time.
To summarize, T1 remains 3.38 damage / CR. Unless you treat CR 1 as part of the...