While that's ok, I think that there should be normal quests with custom monsters, with the rewards you would expect for them (wings, plates, scales).
But the thing is, we would need to have the custom creators go back and add in roughly the stats for the equipment made from said parts would be (Damage/Element/Status/Sharpness for weapons, and Defence/Ele Res/Skills for armors) per rank of monster. This could pose a problem for Ranged weapons and things like HH, but are still do-able. But even then, that's a stretch.
So, for very well made apps (with the equipment list) we can probably do normally. But for the rest, I say training-style would be a good option. Though, they would have to go back and add that stuff.