The export and import functions are not complementary, i.e. designed to work together.
Export is for retrieving data from Dolibarr for “some other purpose” or software, and so it is highly unlikely that the fields it exports are everything that you need. Really it should export everything possible and then you can manipulate the data with other tools. Or, you can modify it to suit your particular use.
Import is for replacing manual data entry. I have just submitted an update for third parties and products to include the essential fields (for multicurrency etc.) I found lacking when compared to manual entry.
https://github.com/Dolibarr/dolibarr/pull/10261
You only need the /core/modules/ files
I did not include all the possible fields as I don’t need them/they were not essential. But, I added extra information to the example CSVs and formatted the code so it is easier to read and modify.
So, you need to prepare your import csv based on the example import csv, not on the export csv.
