Request: Move sidebar switcher buttons back to the top
In #947 (closed), it was requested to move the sidebar switcher buttons (thumbnails, annotations, bookmarks, attachments) to the bottom of the window because having at the top is imposing and disruptive. An alternative take is that having the buttons at the top of the window is more convenient, as it keeps them close to the headerbar buttons and therefore reduces visual distance between different buttons that will likely be clicked on for related tasks.
For example, it is not uncommon to click the sidebar button to show the sidebar, and to then want to view a different sidebar type. Currently, one has to move the mouse all the way to the bottom of the window after clicking the sidebar button to view another sidebar. Keeping the sidebar switcher buttons at the top of the screen would keep them close to the sidebar toggle button itself, so that opening the sidebar and viewing a different sidebar would involve much less mouse movement & eye scanning than it does currently.
Precedence for having sidebar switcher buttons nearer to the top of the window is in Firefox, which displays the title of the sidebar at its top, which also doubles as a switcher.