My understanding is that generally (with the possible exception of starters) yeast nutrient and energizer are not really needed for beer, as the barley provides basically everything required.
However, is there any possible downside to adding them? Obviously using it when it adds no value is wasteful but is there anything in yeast nutrient or yeast energizer that would adversely affect the beer if too much is present in the final product?
On the other end, the yeast energizer I have lists its ingredients as diammonium phosphate, Springcell, and magnesium sulfate. Of these, magnesium sulfate sticks out as something that might benefit hoppier beers. I would imagine the amount in the yeast energizer would be relatively small, but maybe they could be high enough to make a noticeable difference?
More generally, are there any possible flavor impacts of yeast nutrient or yeast energizer if added to an otherwise normal batch of beer? I'm mostly thinking all-malt beer, but if this might be different for wheat beer or similar then I would be interested in that as well.