You aren't going to have a problem w/ too much protein. "Extra" protein is good for easing molting, its good for weight gain on meaties, its good for your roosters, its good for their health generally, and it helps them with the winter months.
16% layer feed is the absolute minimum average diet (that is, its the cheapest they can feed the birds for!) for commercial layers in commercial conditions with a productive lifespan that is rather short - at which point, they are replaced with fresh layers, while they go on to become dog and cat food (I assume). A year and a half, by many estimates.
20% protein is the highest you will likely find around you commercially, as grower/starter, as flock raiser, as all flock, etc - not because higher protein is necessarily bad for chickens, but because it rapidly becomes more expensive than the market will bear, because the cost/growth ratio starts falling off pretty fast (I've seen 24% specifically for raising meaties to market weight in 2 months), and because a significant amount of research out there strongly suggests that protein greater than 24% is associated with increased incidence of "angel wing" in ducks, making a "high" protein All Flock mix rather counterproductive.
Game Bird mixes, as
@MysteryChicken observes, are up to 30% protein for rapid weight gain on turkeys and the like.
I mix my own feed based on what's available from the local mill at a good price, and routinely incorporate a bag or two of game bird into lower protein feed to up its numbers - my flock seems to appreciate, my wallet does not. 18-20% protein provides me the best mix of weight gain for the price while maintaining an otherwise healthy flock - where exactly it balances out varies with feed price - which seemingly changes weekly.
Mealworms are a great protein source, but like BOSS, they are VERY high in fat - one of the reasons treats are cautioned against - its easy to unbalance a diet, while meaning well.
and my flock (in Sig, below) free ranges too - its how I've gotten my feed down to just 300-350# per month. Mine tend to gorge for a bit in the AM, or after a rain, then go siesta thru the mid day heat when their bellies are full. I don't recall any news ever about backyard flocks suffering health effects after gorging on a cicada hatching, or a locust swarm, though such things have happened for centuries. Think its safe to relax on that score.