Feeding question

You can start to now. Just if they start to spit up or not drink it’s too much.

I would start now and just feed them on demand as much as they want. Don’t let them go longer than 4 hours or so but let them eat what they want. Amount wise

If they seem to still be hungry you can absolutely boost them now, my 1 month old as of yesterday, and is 4 weeks does 3.5 every 2 hours and yes she drinks it all, sometimes just leaving half an ounce or none at all, she does not throw up at all barely ever honestly and when she is no longer hungry she will not take the bottle at all, so yeah hays what it takes to satisfy her and make her full