I was in that situation:
I had a song in a pfl window, but I switchet focus in to a differend aplication, and by this time song stopped. And it’s a problem, because PFL window hiden, and I am not able to switch it back from Keyboard, and when i am pressing a CTRL+P key, PFL window is opened, but next, and 2 songs, from previous and currend PFL are playing.
The Ctrl+P keystroke for closing a PFL window is captured by the PFL window itself, so it must have focus. There is no way to work around this (other than defining a custom hotkey for PFL CLOSE).