I actually think, since these styles are
Yamaha .sty, that we should stick to the
Yamaha format of drums on channels 9 and 10(where the main drum track on ch.10, and
secondary percussion usually on ch.9);
and also to use soundfonts/wavetables with XG drum mappings. This would eliminate converting to GM, and styles would need less tweaking.
The creation of such an all-emcompassing
XG drum soundfont/wavetable might initially be a lot of work, but it will save much time and aggravation in the long run.