Not sure if this will help in this environment, but we have several embedded systems based on Raspberry Pi (as the Leo) and we solve the abrupt shutdown problem simply by forcing a filesystem check on every boot. It makes the boot a bit slower but it also avoids a lot of headaches. For instance we have a RasPi used as media player on a Digital Signage totem which is restarted automatically by a pysical power cycle every day, and it has been operational for years now…
To get this filesystem check the easiest way is adding the word “forcefsck” (without the quotes) at the end of the text line in /boot/cmdline.txt in the SD card (in the FAT partition, you should be able to do that even from Windows).