Can the system UI Tuner be enabled on the 6p?

Does anyone know how to enable the system UI Tuner on the Nexus 6p. I tried to press and hold the gear icon at the top for a long while but I was unable to ever enable that setting. Is there something I'm missing or doing wrong? Also I'm wondering has anyone been able to get picture in picture to work on their 6p? That's partly why I'm trying to enable the system UI Tuner in hopes that I could activate that setting with my new Pixel launcher I've downloaded from the XDA site as a apk file. One of those nights for me where I couldn't sleep so I've been tinkering with the 6p most of the night. Any help is greatly appreciated. Thanks.