I'm using the LibraELEC image on a new Pi3.
When I navigate to the power icon (using mouse on the desktop, or the corresponding button on a remote control) it offers a menu for cancel, reboot, or shutdown.
I choose shutdown, and a few seconds later the monitor shows “no signal”.
Ok, now how do I turn it back on again? Pressing the same remote button does nothing. Moving the mouse or pressing keys on a keyboard does nothing.
What would be useful is a sleep mode like I get on my “regular” HTPC. Any user input device will wake it up, and it instantly remembers where I was. And if I do perform a full shutdown, there's a button on the ATX case to start it again.
I want a useful sleep/standby mode on the Pi3/kodi, with an automatic no-activity timeout. And if I must reboot rather than sleep, it certainly needs a way to turn it on!