I couldn’t find the post, but according to my memory Michelangelo once wrote that there is no risk to switch off Volumio without shutdown because Volumio runs from RAM only and does not write to the sd card except if one stores something. However, on my system (RP3, Allo Kali & Piano 2.1) the green LED which indicates operation to the SD card is blinking quite often. Therefore I would pleased to know whether there’s a risk the switch off without shutdown.