Welcome to the Community Forum.
While I cannot provide any help with the PWM question, I just wanted to use the timely opportunity to strongly recommend to make sure what you buy is not a business phone still locked to a business’s or organization’s IT admin. This is especially relevant if you ever want to install a custom ROM (alternative operating system) on the device.
EDIT: For the “why” 
Trying to install e/OS - #12 by mike_1312