Hmm.. tbh I think milk kettle for formula milk is complicating a simple chore, because you will need to prepare the formula beforehand for it to be heated. Besides that, formula milk should be consume within the hour(room temperature) or refrigerated properly(alot of factor for bacteria growth). For practicality sake, we use airpot for the boiling water and kept another water flask(room temperature) to mix with the boiled water. It takes only 5-10mins tops.
Wee Kiong Tan