For clarification, excess protein would be in the 30% range for protein delivered via real food, that is, things like grains, fruit, veg, meat, fish. It would be up to 5 times lower for a uniform substance, however presented, whose nutritional value was added as individual synthetic amino acids.
Why does it matter? (This has nothing to do with my personal values, btw; just for the record, I eat KFC when I feel like it, for example.) Because the first big discovery of nutritional geometry was that animals in the wild select a balanced diet from amongst the various seasonal foods available to them. They have a target nutrient intake, and most species prioritize protein, such that once they reach their protein target, they stop eating, even if they are then short on carbs or lipids. The target moves of course, meal by meal, day by day as they live and change. Through their biological appetites they seek a compromise, normally and overwhelmingly, between carbs and protein; lipids are relatively unimportant. They instinctively get as close as they can to their target intake, given seasonal food availability in the wild or by design in the lab. And all species seem to have a real aversion to excess protein. Why? Because it shortens their life. (On the other hand, it facilitates reproduction; hence the compromise for most individuals.) From yeasts to humans, with few exceptions found so far (this is work of the last decade), a low protein, high carb diet leads to longest life and the most healthy mid- to old-age. It does not facilitate reproduction however. (Which explains why there are layer feeds and breeder feeds, btw.) But synthetic animo acids are up to five times more damaging than natural proteins in natural real foods. They don't tell you that on the label. Perhaps they don't know it.
And with that I will bow out and leave you get on with whatever you choose to do.