Impress lacks a button action to perform UNO command .uno:RestoreEditingView that is assigned to accelerator F5_SHIFT_MOD2
Suggest a menu button:
"Return to last edited slide... Alt+Shift+F5"
be added to the Main Toolbar "Veiw", or Impress only main toolbar "Slide Show" item.
However, this button might also be positioned onto the Impress View tabs menu--currently proposed for rework under bug 87672
Thanks for opening this enhancement.
a bit of a code pointer in Samuel M.'s http://cgit.freedesktop.org/libreoffice/core/commit/?id=c41dfa1265c6de8045f3a7bfd248ec0f8d9fc8c3
If you are going to add to the Main Toolbar -> Slide Show then should be simple menu addition in: