Raw White Points
It is unlikely you will ever need to use the Raw White Points tool other than for diagnostic purposes.
The white-point correction adjuster scales the current white level for all channels. It scales the raw samples linearly after black-level subtraction and can be used to simulate a new white level. This can be necessary if RawTherapee's raw decoder has an incorrect white level, which can happen for new or rare cameras. Flat Field correction may also, in some cases, as a side-effect, scale down raw samples such that blown highlights become discolored (usually magenta/pink); in this case this setting can be used to scale up the raw data so it hits the white level again.