3824691 - What is the impact of the setting ''Synchronize Name Fields between Travel and Expense'' and "Employee Import Updates Name"?

We are sending updated values for fields First Name, Middle Name, Last Name, Name Prefix, and Name Suffix, but they do not show in Concur, while there are no errors on the import. Other values update correctly.
I understand there is a setting titled Synchronize Name Fields between Travel and Expense and Employee Import Updates Name. If we change the setting to No/Yes, what is the impact?
Which name fields can be edited by the employee and how often? For example, is the first name editable? 

Information on the setting ''Synchronize Name Fields between Travel and Expense'' Why Title, Name and Suffix don't get updated via Employee Import? , KBA , CON-TRV-ADM-USR-PRO , Profile , Problem