Since plugins became available on mobile, I often click on notes while another note is already open. When I'm done, I often need to press the back button 5 or 6 times, in order to be able to change the notebook I'm in or search for a note.
I'm not sure, how this could be improved since being able to return quickly to the note you just came from, is also very useful. But maybe like a long press on the back button could take you back completely or something?
Maybe it's a niche problem, but I thought I'd throw it out there for the devs to consider.