I like the method of restarting VoiceOver by clicking the sleep button six times quickly.
On iOS 10.1.1, it works to click it five times.
On iOS 10.2, it does not work.
I use iPhone 7 on iOS 10.2 with VoiceOver, in Japanese language setting.
I asked Apple accessibility team by email.
I got reply'
> In our testing on iOS 10.2, we were able to press the Sleep/Wake button five times quickly to reset springboard.
How about in your environment?