Hi Fernando,
if you define your integration scenario step not with option "SAP Business One Single Transaction" all B1 DI API calls are conditionally until the "commit" runs at the end of the scenario processing.
That means all operation might get rollbacked. Therefore please avoid to have two DI API "Insert/update" calls within one step and "SAP Business One Single Transaction" deactivated.
As B1 RecordSet relies on DI API connection, it's much slower than a JDBC SQL retrieval.
To retrieve the B1 object call result you could also work with B1 object call method "Synchronous Retrieval": From performance point of view it's not slower than the B1 ResultSet SQL.
Best regards
Bastian