If memory serves, the sfizz plugin only supports sfz; not sf2? Either way, I've found the Calf Fluidsynth plugin (lv2) to be completely usable. Not sure if it's the most optimal method as I do not use the instrument menus from inside Qtractor. I simply load the Calf Fluidsynth LV2 into the track and then use the plugin itself to load the sf2 or sfz I'm interested in working with.
If memory serves, the sfizz plugin only supports sfz; not sf2? Either way, I've found the Calf Fluidsynth plugin (lv2) to be completely usable. Not sure if it's the most optimal method as I do not use the instrument menus from inside Qtractor. I simply load the Calf Fluidsynth LV2 into the track and then use the plugin itself to load the sf2 or sfz I'm interested in working with.