That's not how this works. Power throttling is one of the techniques that can be employed to keep the CPU/GPU and other system temperatures under control. It's is not a lack of available power from the battery or charger rather it's a control mechanism. Battery charging is a separate issue and from my testing of the Surface 3 the charging circuitry will limit the max charge rate so using a higher powered charger does not speed up charging and I would expect the same behavior with the Surface Pros. There is an exception to this with the Surface 3 when using the docking station it charges through a different path an does charge at a higher rate. The Surface Pro's only have the Surface Connect to charge through so it's the same either way. The higher capacity chargers for the Book or the Dock are to provide power to other components like dGPU, extra fans, USB drives, etc.