Indeed !
Also, I made a quick modification ov vtkDebugLeaks that changes ConstructClass(const char* name) into ConstructClass(const char* name, vtkObject* key) and store them into a std::map<std::pair<name, key> > in order to be able to track them the same way you track other classes.
Well, ParaView took 30 minutes to just open, I was not able to test what I was trying to test and gave up.
I’m going to need to find another way to track this leak.