It might be more about not losing mats than improving HQ rate imo. If you make 40 NQ when you try to make HQ, you lose all the mats on each NQ and it's usually hard to sell. If you force break on NQ, you might lose some or nothing beside crystal (thats why this enhancement also has -15% material loss) and in 40 tries you might for example lose mats worth of 10 items.
Yep, this. NQs are generally considered worthless, so intentionally breaking on those and retaining mats for a potential future HQ is the way to go. Stacking -material loss with the shield enchantment, food, HQ crystals, Ionis, rings, standard Moglification (depending on HQ tier) gives you pretty good odds of keeping the mats unless it's something like a Superior recipe.