With ACR it's even "worse", as temp/tint is derived using the color matrices in the DNG profile. So if you change profile the temp/tint derivation will change, as color matrices are not exactly the same. As ACR store temp/tint rather than the multipliers when you change profile the multipliers change, but temp/tint stays the same.
There is a way to cater for this though. In a DCP profile with forward matrix as well as colour matrix, the latter is only used to convert from XYZ to camera space and thus only to do the whitebalancing by temperature/tint. The actual profile transform uses forward matrix. This allows to share the same colour matrix across several profiles for the same camera for example and get repeatable WB across profiles. This can be changed after profile has been built by using dcptool for example - convert profiles to XML, copy the colour matrix (but not the forward one) from one of them to all and convert the XML to DCP with dcptool again. It would be very nice if Adobe procucts would actually store WB in the multipliers as opposed to temperature since it will be profile independent WB but I don't think it will happen.
For myself and dealing with multiple Kodak cameras I had a little tool written to convert between temperature/tint and camera WB multipliers for a given profile. Example:
c:>dcrdcpwb.exe Kodak_SLRn.dcp tuscany.DCR
Profile name: Kodak DCS Pro SLR/n - RPP
Camera Model:Kodak DCS Pro SLR/n
WB presets:
Daylight: Temperature = 4962.92K, Tint = -15.8262 for camera neutral (0.814638,1,0.646778)
Tungsten: Temperature = 3073.79K, Tint = -38.7456 for camera neutral (1,0.961426,0.51123)
Fluorescent: Temperature = 5222.13K, Tint = 7.5804 for camera neutral (0.778411,1,0.625618)
Flash: Temperature = 5213.96K, Tint = -4.44951 for camera neutral (0.789819,1,0.644813)
Auto: Temperature = 5670.06K, Tint = -31.5093 for camera neutral (0.793308,1,0.714674)
What makes situation even worse is that ACR/Lightroom WB settings are interegers and for some WB settings the conversion of them to multipliers can be quite crude.
