Re-design the application. It should appear in full-screen, max possible width, either in reading mode, or in editing mode, one should be able to switch with a command or click. Auto-turn pages to reading direction, enable both turning directions, if page is half turned, then on mouse over show the turned version. If in editing mode, allow comments and auto-save these. What is desperately missing is the showing of signed pdfs - signature panel should always be there - if I open with Edge, I see the signature, if with Adobe Acrobat - I see nothing, this is a huge bug, should have much more attention. Enable quick marking yellow and underline red, also change of these colors. Auto detect by printing everything - still allow user to change printer.