Unlike all other Snowflake operators, S3ToSnowflakeTransfer requires the usage of schema instead of letting it be an optional variable that when passed would be used, and if not, then connection metadata is used. 

I can be assigned on this if needed. Keeping this up here so this doesn't go unnoticed. 
airflow/providers/snowflake/transfers/s3_to_snowflake.py
:ref:`Snowflake connection id<howto/connection:snowflake>`
    :type snowflake_conn_id: str
    :param role: name of role (will overwrite any role defined in
        connection's extra JSON)
    :type role: str
    :param authenticator: authenticator for Snowflake.
        'snowflake' (default) to use the internal Snowflake authenticator
        'externalbrowser' to authenticate using your web browser and
        Okta, ADFS or any other SAML 2.0-compliant identify provider
        (IdP) that has been defined for your account
        'https://<your_okta_account_name>.okta.com' to authenticate
        through native Okta.
    :type authenticator: str
    :param session_parameters: You can set session-level parameters at
        the time you connect to Snowflake
    :type session_parameters: dict
    """
    def __init__(
        self,
        *,
        s3_keys: Optional[list] = None,
        table: str,
        stage: str,
        prefix: Optional[str] = None,
        file_format: str,
        schema: str,  
        columns_array: Optional[list] = None,
        warehouse: Optional[str] = None,
        database: Optional[str] = None,
        autocommit: bool = True,