[Les]

Yes, can calc a die temperature but if not the temperature in "region of max power dissipation" then another offset is required. Our(pH's) temperature will only be the temperature that processor manufacturer allows us to see.
Still worth having - but I am not doing the work.
The difference in temperature of our(pH's) position of measurement and the temperature in the region of maximum power dissipation will be unknown to us.
I only guess that this is the temperature of "max power region"to which "well documented thermal characteristics of the TTV" applies (quote from memory).