Can custom fields for the Leads module in SugarCRM be mapped to stock fields in target modules?
At this time, no, custom fields added to the Leads module cannot be mapped to a stock field in another field. To work around this, remove the stock field from the target module and replace it with the custom field. Existing data can be moved from the {module}.{field} table to {module}_cstm.{field}_c table to maintain the history.