I click accidentally on this button dozens of time every day when I click it instead of the button right next to it, when I want to go to the first page of a doc. I have never wanted to share on Bechance, and am unlikely ever to use this option, so I find it very inconvenient that the button is placed in such a prominent position.
There's not way to removed an unwanted button, I'm afraid.
Better to use the keyboard shortcut for First Page. By default, it's Shift-Cmd-Page Up (Mac) or Shift-Ctrl-Page Up (Windows). Or choose Edit > Keyboard Shortcuts > Product Area: Layout Menu and give it a shortcut of your choice.
Thanks Steve. Good solution.