It’s perfectly normal! Not to mention formula, even breastfeeding under a cover is perfectly normal. But yeah, this is Singapore what can we expect right.. Whatever we do, we will get stares or unnecessary judgement so just ignore them.
If baby drinks too fast, can consider downsizing the teat. I downsized my LO’s teat when she’s 1m old back then. (I didn’t know there was a smaller size teat 😅)