low prio feature request:
add an option (checkbox) to add Left Table RowID and Right Table RowID as additional/new columns (or better but less suitable for the common user: a collection column (array of 2 strings) containing the RowIDs)
(for most operations an additional column can be generated via RowID node but this is very inefficient if the amount of data increases, because the RowID is present already anyway and you dont need to modify a data model)