I now have my koreader working like a well-oiled MACHINE!
It's a tribute to it that I hardly even use the default factory interface any more. (see Sidebar below)
I've spent a lot of time setting up my prefs/settings so they're juuuuuuuuust right - esp gestures.
Is there any way I can export all these sweet sweet settings - either in the app or copying some file?
I did look in the menus and on this forum so sorry if I've missed it.
(If someone knows better, feel free to just use THIS system of description:
Menu 1 > Submenu 3 > dialogue X)
Congrats to the devs for this thing of functional beauty they've made!
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SIDEBAR: SOME ('RANDOMISH') REASONS I PREFER KOREADER NOW 
In the factory interface I used to get quite obsessed about allocating things to shelves - esp trying to make various shelves of what to read next, organised by topic. Shelves ARE a good feature. But honestly, trying to do this using Calibre with all the books I have was quite a task! (Even though Calibre is phenomenal!) I kinda gave up...!
But turns out I find the simple Koreader HISTORY achieves what I wanted quite well. If I want to make sure to read a book, I just open it once. Then it's there in the list. Somehow, also: organising things by most-recent just works well.
Then there's Favourites if you want a longer-term record.
For overall organisation, I actually find a simple FOLDER system just as good as the factory interface, if not better.
One thing I've been noticing even in Windows lately is how useful it can be just to go to the top/root folder again and start afresh, finding whatever you need via 'the journey'
The fact that Koreader EXITS a document back to the folder it was in is also VERY helpful. You will automatically see other things you might want to read on that topic
Overall Koreader is a very satisfying experience. It even FEELS more dynamic than factory!
It's a thing of beauty !