Version Picker Custom Field can't be CSV imported with value or custom field ID

User is getting:

FAILED: Customfield value 6.2.0.4 is invalid
[22:31:39] com.atlassian.jira.issue.customfields.impl.FieldValidationException: Version Id is not a number '6.2.0.4'

when trying to do a CSV import whilst mapping to an existing custom field of type version picker.

Workaround explained in JSP-977 also didn't work.