Right now, it only uses the CPU temperature, not the package temperature. Personally, it really doesn't bother me, with a 5950X running over 200W peak and a Ryujin II 360; I get plenty of cooling out of it and can just set the temperature for 100% lower on the curve if I need more. I have my pump, VRM fan, and rad fans set to 100% at 75C, which results in a peak package temperature of approx 85C (which I believe is safe for Ryzen 5000). I also swapped the supplied Noctua NF-F12 iPPC-2000 fans for the quieter NF-A12x25 (that's the new next gen 120mm all-purpose fan) and the NA-AVG1 radiator gaskets to reduce the noise a little at 100% (the iPPC fans are great, but noisy at full speed).
Honestly, I don't think it's all that important which of the 2 temperatures are used, it's just a matter of tuning the curve appropriately (and the auto-tune seems to work ok with the temperature it uses, as a starting point).