Modify column on the run

[subdesign]

Hi,
Is it possible (maybe with --postrun) to modify the seed result on the run?

For example: in the source DB I used language_id int values like 1,2,.. , but after a refactor to enum, field name should be language and value 1 is en, 2 is de etc.

I created a postrun event, but nothing happens if I dump or dd it.

Any idea? thanks