For NLS, limited/partial use in feedings can really only be beneficial. The more variety, the better I always say. However some of the claims made my NLS, such as to use the product as the only food source, I disagree with.
As anyone seen the video produced by NLS? They make some very bold claims, such as keeping a number of angels/predators on exclusively NLS for many years. Also they nourished a sickly Moorish Idol to health in about 2 months feeding only NLS.
As for the trigger being pinched at the top, after at least a year of strong feedings, my Lei trigger still is pinched. It's very easy for triggers to lose the fat storage, but seems like it will take an eternity to put back on. I noticed many triggers kept by 'good' fishkeepers have the pinch as well.