No, and I don't. I'll explain why I chose not to.
The camera module is already made with Sapphire albeit with some impurities. As Sapphire is quite scratch resistant, approx 9 on Moh's scale, it does not really get scratched with most daily objects like keys and coins. Diamond being the hardest, 10 on Moh's scale, will definitely scratch it.
Tempered glass protector is at most around 5 to 6 on Moh's scale. It scratches much easily. And by sticking the protector on top of the camera module, you are effectively reducing the overall scratch resistant on the cameras. The last thing you want is any scratch marks on your photos.