I actually also own a kobo and have been running KOReader on it for a couple years now, but my memory is that when I first got it I booted it up and it requested to be connected to the internet, then wouldn't allow me to progress without logging in through a 3rd party (there were many offered, walmart.com was the first option listed). I remember having to do something weird to bypass that (removing a .db file I believe after connecting via commandline?), and then ending up in a state where I don't need to connect to some company's cloud login but I also can never connect this device to wifi, ever, or it will do that again.
Are they more open these days?