So I know this is old news, but I still encountered a large enough group of people saying that the 45w charger is useful for quick charges at under 60%, and that it could get you an extra 10% on a 15min charge, so I decided to get one for myself. Keep in mind I never discharge my phone under 20% and only charge to 75%. I have my phone record charging wattage, battery temp, and percentage of charge and log it to a file. I made sure my acc magisk module had a temp cutoff of 40C and the cooldown ratio was null.
The highest wattage this charger has ever delivered is 32W. It very rarely exceeds 25W and almost never achieves wattages over 30. My tests were done in a cool room and the battery temperature never exceeded 36C.
I believe the highest charging wattage I have achieved with the stock charger is 23. That makes charging with this enormous 45W charger and its thicker cable a bit of a joke. Seriously this thing is huge, and a waste of money. I paid $30 and Im not happy.