You do not understand at all how ZMI works. Read the images attached to the OP and all of the ZMI tool tips.
Z* Custom Columns are ONLY updated by importing a Zotero .csv export file.
.ris exporting does NOT update any ZMI custom colums.
The Retrieve action adds 2 Calibre Identifiers. My post above clearly shows the Scalzi book with NO Z* custom columns BUT with 2 special ZMI Identifiers, including zcollection and the ebook's zkey for its file.
DaltonST
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