EasyMorph makes a distinction between empty values and empty strings, but it exports both as empty strings. Instead, there should be an option to specify how to export empty values. For example, when importing a CSV into MySQL, you can specify null values using the NULL keyword or \N. We should be able to specify the character or characters to use when exporting empty values, to make it easier to import null values into other systems.
Currently, I’m working around this by using the Modify Columns transformation to manually replace empty values with “NULL”. However, since this is specific to the export format, it should really be done in the export options, not at the field level.