maybe sharing the underlying use case may help the community to come up with creative ideas for that?!
Happy to do that, Stefan.
The use-case is to flag out all the items of a product when the higher level product's status is Inactive.
So when an user updates the status of product as 'Inactive', all the items that belong to the product will have one item flag set.
Did you consider looking into possibilities using the SDK and implementing a post setter for such product field specific updates? It may be the most stable option to achieve this.
If DQ: My take would be slightly different. Listen to a change of that product field, let a product DQ rule listen to it, inside that product DQ rule use the product identifier to query all items below and update their fields via a JavaTransform using the internal REST API client of Product 360.