OK thanks, I'll try and parrot back what you told me, and throw in a couple suppositions...
KSM is the e-reader equivalent of Grub 2 for computers. It allows dual-booting, and you can choose a default firmware (Nickel or KOReader) which gets auto-selected when you turn the device on from an off state.
Settings in both Nickel and KOReader control when your device gets turned off after a sleep duration. When you wake the device from a sleeping state, it returns to the page in the book in the firmware you were last in.
KOReader allows you the flexibility to choose your defaults, whereas Nickel (Kobo firmware) sets these for you (outside of what you can choose in "Settings").
Settings in KSM allow you to choose which is the default firmware, duration before auto-select, along with other options.
Sorry for the back and forth, I'm just afraid of bricking my Aura original. It's arguably the best e-reader Kobo ever made, and don't know how hard they are to replace these days.
