Adding rice cereal to formula

My son is 3 months old and I wanted to add rice cereal to his formula. He is already 15 lbs (was 10 at birth). He’s still waking up every 3-4 hours and he spits up a lot of his milk, so for both of those reasons I want to add the cereal.

Now my pediatrician said I don’t need to unless he’s not gaining weight. But he’s also said some other things that aren’t correct like how much to feed the baby.

I have read some articles saying it’s dangerous but honestly how is it dangerous if women have been doing it for years? I’ve talked to so many women who started doing it even as early as 8 weeks. Not a single one has reported choking or any gut issues with their children. Just a really calm baby who starts sleeping through the night.

Anyone ever add cereal at 3 months? If so how should I do it and what brand do you recommend?