I read 1-2 thousand pages of academic material a month using DTTG and find a great deal of value in your app. Thank you for making it. The highlight and note annotations I make on the iPad are available to me in the desktop version, etc, and save me many hours of time as well as making possible a research modality that is truly revolutionary. it is nearly perfect.
However on my iPad Pro 11 I am constantly accidentally hitting the thumbnail bar when switching apps or pulling up the dock or just by accident while reading. This results in my losing my place in the document I am reading and can often cause me to have to spend several minutes finding my way back.
In my view this should never happen by accident.
I have never once used the thumbnail bar to any positive effect… it is too course a navigation interface. The thumbnail view available in the top bar is far better. It is far too easy to activate the thumbnail bar and the result of accidentally touching it is… awful!
I propose that you make the thumbnail bar disable-able via the settings menu, and consider disabling by default. Doing this would easily save me hours a month and eliminate the only downside to my most used and favorite application. All best.