[DNSB]

The real factory reset is my recommendation so you are starting from a known point without any other changes that may have been made to the system. As for KFMon, I don't use it at this point and last time I played with it, I grabbed a copy from the GitHub page which was the same as the one in the OCP packages at that time.

You don't need to rename the file since NickelMenu really doesn't care. I remove the extension to match what other programs do for NickelMenu config files. As for what the commands do?

Dark Mode switches reading to white on black text but does not invert images.

Invert & Reboot inverts everything everywhere but need a reboot to switch modes.

Import books is useful if you do not transfer books over USB and need to trigger the Import books action. I use it occasionally when I download a book using the web browser.

USB Connect allows you to reconnect your Kobo to your computer without physically ejecting. Safely eject but do not physically unplug, wait for import, etc. to complete and then use USB Connect to reconnect. Saves wear and tear on the connectors.

Reboot and Shutdown are pretty much self-explainatory.

You don't need to keep anything you don't want. nm-kp is a sample config file with options that are commonly used.