There is virtually no nutritional value in baby rice, to be fair. It's is literally a "filler" and can lead to a constipated baby. There are more fats/calories in breast milk.
Also, LOs with reflux (especially if it's not under control) do often prefer to feed little and often as the milk can neutralise any acid that is coming back up and they also know full well that if they take a big feed, it's likely to come back up again, whereas a smaller, more frequent feed might be more likely to stay down.
Did you mention the reflux when you were asking for advice on the sleep side of things? And have you been getting any support from the
Colic, Reflux, & Crying board?