Allow multi-select survey questions to write to SF object

We use the rules engine to upload NPS survey responses to a custom SF object (people need to see that but don't need access to the rest of Gainsight).  One of our additional questions asks about top improvement areas.  It's a multi-select list.  Current functionality does not allow that to update properly on additional runs.  We'd like to have that be possible so data doesn't have to be downloaded and uploaded each time.