I think no through regular Contact Import; I can't see how through API CSV Import; if anyone has any other thoughts that would be great.
Seamus told me to try ->
/civicrm/import/custom?reset=1 and that looked promising! -> but trying to import dates I run into an error message that makes no sense -> I got a "value: 2020-01-01 is not of the right field data type: Date" That custom field is configured as a Date field and 2020-01-01 is a date 😊
Do I need to sql my way through this?