I see that you are going to open threads until you get the answer that you want.
On the island of Menorca, there is a particular problem with cats in that holiday makers,see the kittens of the feral cats and feed them.This is fine until the end of the season when the kittens are left to the Islanders to support ......some do and some don't.
We have at the moment seven feral kittens who are fed on the road at the bottom of some steps.They are about 6 months old now, healthy, fit with lovely coats and are more appreciative than our own two.
The cats are fed every evening and alternate mornings and biscuits left in a feeding device. These cats are healthy on their diet.
We also attend a cat sanctuary of about 75 cats, on a rota system, a mixture of adults and kittens.
I am not a vet or an expert on cats, but my opinion remains that you are overfeeding your kittens.