The general rule is All editing of data must be done in a notebook (i.e. not manually in Excel).

I believe there is an exception for the training data. Amy_Bray Comments "Both the public and private test sets have been manually reviewed and corrected to align with the cadastral plans. Minor name discrepancies (such as inclusion or omission of initials) remain, which is why WER was selected as the evaluation metric. The training data may still contain inconsistencies, but the test data have been cleaned to ensure reliable evaluation."

Without official Zindi confirmation for this specific training set edit, this remains a wildcard play.