There is a new option Ignore non-existent variables on the Execute template dialog page. If the option is activated, only variables that actually exist in the project are assigned to the classification.

The page is called up either on the Classification tabbed page via the Execute template button

or via a directory in the structure tree using the context menu command Batch run classification with templates.

You can find details on this under Section 5.12.6.1, “ Classification tab page: Manage and execute templates” in eCATALOG 3Dfindit.