Customize hotfolder AOP in Hybris

[drbernasor]

I am trying to customize the HEADER_TRANSFORMED step of hotfolder processing. I want to use my own class instead of using the OOTB ImpexTransformerTask:

<aop:around method="aroundTransform"
            pointcut="execution(* de.hybris.platform.acceleratorservices.dataimport.batch.task.ImpexTransformerTask.execute(..)) and args(header)"/>

I created my own aop.xml (with the pointcut now using my custom method) which I imported as resource in the xxx-spring.xml. However, it is still the OOTB ImpexTransformerTask that ends up being called. Am I missing some step?

Thank you!