The newest release fixes adding decks:
https://github.com/Szybet/sanki/releases/tag/v0.0.3.1
Images need to be resized while creating the deck, I will add in the future an option to resize them in sanki.
As for sleep, it's pain to add, look here for InkBox implementation
https://github.com/Kobo-InkBox/inkbox-power-daemon
The author of Obenkyobo had problems with it too soo... I don't plan to add it