The new functionality relies on database case sensitivity while the old masking functionality uses double quotes and uppercase characters for table aliases.

With the new masking functionality for SELECT queries, while replacing asterisks with the corresponding column list, you can use the AUTH_QUOTED_IDENTIFIER symbol to decide if the identifiers should be with double quotes or not in the masked query.

The new masking functionality uses a lazy masking algorithm. This means that when a column which is candidate for masking in the inner subquery, the following rules apply:

If the candidate column is not part of the expression, the corresponding column in the outer query is masked.
If the candidate column is part of the expression, the candidate column is masked in the inner subquery.