Joyfull this is an interesting topic, ok I am not planning on feeding the girls just coconut, but as you say about 900 grams of layers a week per bird. or about 125+ a day.
Is there anywhere that advises how many calories are in 100g of feed, ok you could work it out with all the stuff that goes into it soy,corn,etc, has anyone got a typical chart of all the stuff that makes up layers pellets. if you can understand this you can then do some sums of what and how much you could give them as treats.