Mealworms are treats. The general rule is that "treats" should not exceed 10% of the diet, by weight, daily.
Live/frozen mealworms aren't terrible, due to their high water content (60% +).
Dehydrated meal worms, because their nutritional factors are concentrated, can EASILY imbalance a diet. Dehydrated mealworms are usually offered nutritional estimates of 45-50% protein (that's good), 25-30% fat (that's VERY bad). So offering 1/10th of the daily ration (10-12g) as mealworm treats likely increases the daily protein consumption around 4.5%, AND brings up the fat around 2.5%. Since the target fat for a poultry diet is around 3.5%, adding another 2.5% is much more damaging than a 4.5% increase in protein is beneficial.
and if, as most do, you feed more than 10% (by weight)??? Then the calculations are even further imbalanced.
and for those who might briefly think that the addition of dried mealworms helps turn their cheap 16% layer into slightly more expensive 20% All Flock (setting aside the excess calcium from the layer, and the excess fat from the mealworms)? Please tell me where you are finding dried meal worms for $2-3/bag? $6-8 per lb is more common...