https://wccftech.com/ipad-pro-supports-charging-speed-of-up-to-30w-and-its-perfectly-safe/

Believe it or not, but the 18W charger that ships with iPad Pro really isn't taking full advantage of the speeds the tablet is able to achieve in the real world.

We finally thanked Apple for shipping the iPhone 11 Pro and Pro Max with an 18W charging in the box, but the truth is: the phones can tap into 22W of power when needed, so that 18W charger might not be the fastest thing you'd want to stick with. Go ahead, use a 30W USB Power Delivery charger and you can top up your iPhone at the fastest pace possible without damaging anything. Just make sure you are using an MFi-certified USB-C to Lightning cable.