Super hydration soft bread using water roux aka tangzhong 湯種

If you like soft bread and have thought of using bread improver but hate using chemicals here is a great recommendation.There is a craze coming from the Far East to use something called 60deg C water roux aka tangzhong 湯種 to make all sorts of soft breads. I think this water roux method originated from Japan.What is a 60deg C water roux? It’s basically a cooked water and flour paste. Why 60deg C?