If an upgrade is possible, the version of LOAD DATA in IRIS 2022.3 has many bug fixes and improvements.

Just a note...

    LAST_UPDATED TIMESTAMP DEFAULT CURRENT_TIMESTAMP NOT NULL, 

This field will only define the LAST_UPDATED field at INSERT, not for an UPDATE.  You probably want something like:

    LAST_UPDATED TIMESTAMP DEFAULT CURRENT_TIMESTAMP(6) ON UPDATE CURRENT_TIMESTAMP(6) NOT NULL, 

This will cause LAST_UPDATED to be set at INSERT and UPDATE to the current timestamp to microsend precision.

You also need to merge over the index entry in ^rINDEXCLASS($$$UPPER(classname)) to the new namespace.

Don't forget to move all related classes such as Serial classes, datatype classes, super classes, references, etc.