Hi,
When importing and exporting, Could we add an option to include the Row ID (aka primary key)? I believe to prevent accidental updates of records you did not want to update, why not update by something unique, required and auto-generated which is the Row ID?
When exporting, maybe there is a setting to include it like a checkbox and would be the first column.
And when reimporting, Row ID would be an option even though its not an explicitly visible column in Grist. It would be the first option to match on.

