The problem with Star Fox is the huge amount of audio files being streamed from disc.Supposedly language files being removed from starfox zero helped lower load times.
If I recall, removing all but one language, dropped the load time from 40mins to 10min. Then packing the language files into one of the data files dropped it to a normal time.
We solve the problem by packing them into the cpk archives (probably because they get streamed from RAM instead then).