I like KOReader as software but I can't get used to it. This is certainly a viable approach. I have never tried to have it as minimalistic as possible. I still have it on PocketBook, but mostly use a built-in software because it is enough for me.
I would use KOReader more if borrowed books from my library could be read there. For them I need to use their software.
I also have Kobo Clara BW and I love their OS and screen, but I can't read borrowed books there at all. So I have a mixture of everything, I read on both devices and use sync only with books I can read on PocketBook.
I know I can use sync in KOReader and install it also on Kobo, but for now, I don't need that for my reading habits. I guess I like to switch devices and adapt to them. If the book is interesting, the device and OS do not matter at all
