@MelissaC I’m observing there may be 2 separate issues or questions here.
First, there’s a concern about accuracy, which can be mitigated with a solid Bionic Rule or a well-configured SFDC Connector. That should ensure the value of the fields is consistent between SFDC and Gainsight.
Second, there’s how the fields are used and populated. If there’s uncertainty about how a field is used, or the SFDC team signals they don’t support a field, then I would be cautious about ingesting that data to Gainsight. Your Gainsight data will only be as trustworthy as your data sources.
Though you can technically ensure field values are syncing accurately (and do so fairly easily), you may ask if you should do this. If your SFDC data is untrustworthy, then that same untrustworthiness will follow the data ingested into Gainsight.