In all honesty and probably a bit off topic but a total solution. Maybe get a better tablet with some battery life in it to sustain your reading, my battery last for 6-7 hours, from 100% to 20% on my Xperia Z4 tablet when I use the app for reading(you know wake up one lazy Saturday and just read until you feel hungry lol).
I personally dislike the design of the app so after you get your tablet with better battery lets just make it easier for everyone and hammer out those naughty qidian app issues cause really, I agree the app is not user accepted in terms of options and ease of access.
Can't say I would mind a next chapter button, don't see myself using it much but who knows I might need it one day.
Anywho got my vote for a rainy day need.