The patch worked at the time of the implementation. Will check again soon. Maybe another rota is applied at some time at launch (I'm not very sure about the platform independant code path followed).
The rest of stuff I can answer
> Info lists like the file manager are still always portrait mode
> The book I'm reading is always landscape mode
In the FM go to Settings -> Screen -> Rotation and check "Keep current rotation across views".
> The checkboxes (which I've seen on my Kobo) for the various rotation "lock" tools are missing
That's platform dependant code. They don't exist on android (like use volume keys to turn pages doesn't exist on kobos).
> If I go to "Rotation" while reading the book, I don't get the various 90 degree / 180 degree checkboxes, but I can still change it from the bottom menu
That happens on all platforms IIRC. On the reader the rotation options are in the bottom menu. The only option you'll see on the top menu is Keep current rotation across views".
> 90 degree / 180 degree check boxes are there for the info list
There's no such thing as a info list. That's called the file manager (or FM). KO has two different apps (reader and fm). On top of that it has different "views" made by a bunch of widgets. All widgets and views (which are containers of widgets) should follow the current rotation of the app you're currently on (reader/fm).
Apps (again, reader or FM) are what define the options you see on menus. So, technically true: on the FM rotation controls happen on Settings -> Screen -> Rotation
Reading OP again I think you will be fine with "Keep current rotation across views". If you read in landscape and your device defaults to portrait you'll see a little rotation artifact each time you launch the app. It is a bit annoying but the best we can get with "nosensor".