Keep in mind that also Body In Element is marked as a non persistence class. From an exported/pre_builder build sql file you will have no instance of Body In Element. In our model compilers we have always performed a first pass translation that for example creates the Body In Component / Body In Element instances. The associations makes it easier to perform other kind of navigations, without checking the Body “type” all the time.
It might be a good idea to remove the non persistence while the number of users increases.