Fortunately i noticed
this random comment, since few ubers can be bothered to report such useful information where it will be used.
Pham: Level 10128 with a 6234 PED chip = Level 16062
WikiTools: = Level 15843 --> 1.4% absolute error or 3.7% relative error
Sweet, that's closer than i expected. I'll refine the prediction curve next time i get more data to see if i can find a fit that gives a result closer to this.