Persist Zoom Level
Every time when opening an Ebook (or re-load it after the session timed out once again ...) I have to adjust the zoom level to get an appropriate zoom level for my display. I use either my laptop display or an external monitor (4K). In either case the zoom level is too high, s.t. I have to zoom out first.
The following features would ease that (mild) pain:
best: have the zoom level persisted in the browser's local storage
good: make the zoom level a request parameter, s.t. I can have the zoom level fixed via bookmark