Having said that, see this Job Spy plug-in GUI Tool that would allow you to update any of the 87 columns in a Zotero export .csv file regardless of whether they correspond to one of the 27 Calibre custom columns that are natively automatically created by the ZMI plug-in.
https://www.mobileread.com/forums/sh...42118#poststop
Obviously, you would have to create new Calibre custom columns to contain the imported data random CSV file column values.
DaltonST