The box is quite hot and I'm not sure is it safe to leave it on all the time.
Besides, the only purpose for this box for me is watching stream TV from my vu+ satellite receiver on another TV with "VU+ / Enigma2 Client" kodi add-on. So if I leave the box on, it leaves sat receiver busy.@kszaq
Stupid suggestion. If true power on/off is not possible, may be you can think about just shutting down kodi and starting it up again with rcu power button?
I programmed a small microcontroller to learn infrared codes and either simulate the hardcoded infrared code or simulate the button press directly. I think this could help you. Also I added a fan control to cool the device. I could provide preprogrammed uCs.