The Multi-Field Binning tool, when set to equal records, will assign any NULL fields to an 'additional' bin
e.g. if there are 10 tiles set then a bin will be created called 11 for the NULL field
However, when this is done it doesn't remove the NULLs from the equal distribution of bins across the remaining items (from 1-10).Assuming the NULLs should be ignored (if rest are numeric) then the binning of remaining items is wrong.
Suggestion is to add a tickbox in the tool to say whether or not NULL fields should be binned (current setup) or ignored (removed/ignored completely before binning allocations are made).