I dont think you are ever going to find it.
Unfortunately, at least to the best of my knowledge, no information exists that documents temperatures of kanthal wire except in some very specific combinations. I.e. for this mod at this wattage using this specific coil. Nothing generic enough to extrapolate to other combinations because kanthal is simply not a temperature wire.
There are just too many variables involved. TC works because the wire itself tells the temp.
Juul (and similar) devices can use temp control with nichrome because they totally control every one of the variables and can therefor test for them in advance.