FOOOFGroup.get_group() does not set the run modes (_debug, _check_freqs, _check_data) to match that of the input object, which can cause errors; while FOOOFGroup.get_fooof() sets the data mode only. Including "run_modes" as a key within the attributes dictionary returned by core/info/get_description() may facilitate tracking of these attributes.
Also, _check_freqs is not included in the docstring of fit.py.