[Patrick C]

Use the following code for toggling:

// Toggle the scrolling behaviour
   // !!! Important: It seems that assigning to cfg is required!              !!!
   // !!!   Simply executing document.Config.Save(); seems to have no effect  !!!
cfg = document.Config;
cfg.Scroll.MoveCursorScroll = !(cfg.Scroll.MoveCursorScroll);
cfg.Save();

// Add a message to the status bar
if (cfg.Scroll.MoveCursorScroll)
  status = "Fixed cursor scrolling is on";
else
  status = "Fixed cursor scrolling is off";

Copy paste to a text file, and save as YourMacroNameOfChoice.jsee
Add this to “MyMacros” under Macros → Customise → Add (under MyMacros)

You can now assign a shortcut to that Macro (under Tools → Properties for All Configurations → Keyboard → Category: My Macros + Commands: YourMacroNameOfChoice

When toggling, the status of the setting is shown on the bottom left status bar.