When you add records using Grid-Add, if one of the records is a duplicate, you receive an error about the duplicate.
It would be very nice to go ahead and allow the good/unique records to be added instead of having to track down the duplicates and removing them from the list first.
The field that is being found as not unique may not be exposed to the grid-add so the user would have to do a lot of extra work to track down what record is the duplicate.
It would be better to let the good records be processed and removed from the grid perhaps, leaving just the problem records in the grid?