Thank you for reaching out to us. The checkbox you are talking about is the parameter ID_BASEOBJECT_GENERATOR_FLAG. The parameter is "sort of" documented for C++ here, but for resources, it is often best to use the Python documentation, as its resource documentation is much nicer. I would recommend also visiting this thread from roughly two weeks ago, as we also discussed ID_BASEOBJECT_GENERATOR_FLAG there and the unusual circumstances this parameters operates with.

Cheers,
Ferdinand