In the Integration Field Mapping List you have only limited fields to choose from. We should be able to add additional fields as required. For instance one that really stands out is there is not a way to map the Account Number field. This is a field that is not usually set by someone using Dynamics 365 Sales, however salespeople may create new accounts there. When that account syncs over to Business Central and the Accounting team populates the Account Number field in Business Central, it does not sync that value to Sales.