I updated the list of forbidden GeometryGym components on the documentation page.
However, the support for GeometryGym is still experimental and in the first stage the focus has been on creation and export of IFCs, see this model. Not all components work reliably, including the ggIFC Importer but as a workaround you can export any geometry as DXF from BIM application you use and bring it to ShapeDiver for further processing.
We aim to have a reliable IFC support in the future and please let us know if you have any feedback.