[itsme]

On my Boox Tab Ultra C 435 dpi still works, but the icons, especially the + button, become very very small compared to the text size, see screenshot.

Like Andreas I cannot scroll left or right. I didn't test scrolling up/down because I only have two libraries to switch between them. 

Even if scrolling left/right would work I would find it much too uninituitive as there's no hint that it is necessary to do that to search for further UI elements.