Hello,
so I created an Extension for tisfc001 and added a after.save.object() hook, that updates CDF (that stores production order group to which order belongs) in tisfc005. It works as it should in -almost- all situations, namely:
1. When a production order group is created.
2. When an order is added to some group.
3. When an order is deleted from group.
But when a group is deleted entirely (from tisfc3550m000) my hook does not get called! Off course all the relevant orders get updated in tisfc001. How is this possible?

Out of curiosity I created the "true" UE DLL script for tisfc001 with the logic updating tisfc005 filled into ue.after.after.save.object() hook and... results are the same. It doesn't get called upon a production order group deletion :confused:

So thing is tisfc001.grid is referenced in tisfc350, and Delete Mode is set to Nullifies, so when a group is deleted tisfc001.grid gets cleared on the database level ignoring DAL completely. Therefore one has to use before.destroy.hook for tisfc350 to catch this happening.