With YASE you can transfer all sample based patches between X and G like multisamples, the samples themselves etc.
All patches with internal ROM-waves can not transfered.
You can transfer note data by saving the 'X' song as a SMF and then loading this file in the 'G'. Of course, specific patches and effects used in the 'X' would have to be re-assigned in the 'G' as waveform mapping is not compatible. (as stated in the previous post)