Custom Groups created in one method relies on the Surfaces that the application creates in that method. Since both options for analyzing Detailed models will create, name and manage the number of Surfaces differently, any Groups created in one method will not apply to the other. If another method is used to analyse the same model, Custom Groups would have to be created again.
Custom Codes created in one method will be available in the any other method as these values can be applied to all model types.