I'm trying to setup some iPad minis (Gen 2) in Single App Mode utilizing Apple Configurator 2 and CasperSuite 9.91.
After getting everything working and the correct app in Single App Mode I've found that you can't power the iPads down. You can restart, reset volume, etc. But if you hold down the power button nothing happens.
My Single App Mode profile doesn't have the Sleep/Wake Button option checked (I think all options are disable?).
iOS version is 9.3.1
I have found that you can turn the iPads off by pressing the Sleep/Wake Button along with the Home Button for about 8 seconds with the iPad unplugged. If you perform this function when the iPad is plugged in, it will just restart. After the iPad is off you can then turn on the iPad by either pressing the Sleep/Wake Button or by plugging it in to power.