As per the other comments it easier to maintain the SQL code than SSIS derivation task and probably better to push the load onto the SQL server.
I know this example was done for training, in a Production environment I would do the same except put the SQL select statement into a stored proc, this makes production changes easier, only the stored proc needs to change, no need to re-deploy the SSIS package(project). The stored proc should also run more optimally than the select script in SSIS.
The environment I'm working has all the sources coming in as text or spreadsheets and then need to convert the type in a data conversion or derived column transformer. Is there a faster way to get around this having to manually convert the types to deal with unicode/non-unicode conversion?