Seriously great work so far Kolenka.
There is something strange with how collections work on the device, don't know if you noticed this, but by default collections are sorted by "added order". This feature actually works on device, but you need to add a book to the collection one at a time.
Interesting thing about this is when I checked my books.db, the collections table has the added_order field null on all these books
Not sure how it's actually working maybe they got lucky and it works just using the default order for they were selected from the database?
Not sure how your driver will work with 'series' calibre metadata, but I'd imagine there might be a bug in Sony's firmware that's not populating this field (and possibly not reading it?) Something I wanted to point out in case you notice any strange behavior -- the collection sort might be driven by insert order, not the actual added_order column in the collections table.
So far you've always been two steps ahead of me so maybe you already are aware of this possible bug in Sony firmware, figured it wouldn't hurt to post it anyway
