In my openion I found that, gap under the keyboard is really useful. If you have automatic screen rotation disabled there will be a popup icon on the right bottom corner of the screen when you tilt the device. If there is no gap at the bottom when the keyboard is enabled, there is a chance to accidently trigger the screen rotation as you type.This popup is on exactly same place where the enter key will be. I am using a third-party keyboard and I am facing this issue.. I will attach a screenshot also.
