That's nonsense of course you can. I had it on my 2017 GSA. I can't recall the steps needed exactly but I had it available on both lines in the LCD. Might be in your BC CUSTOM menu.
Ah you might be correct its in a hidden thingy, just found the counts way of doing it, going to have a go now in the garage.
- Ignition on/bike stationary.
- Press TRIP repeatedly - until the top displays SET UP ENTER
- Press TRIP and hold - to start the SET UP menu
- Press TRIP repeatedly - to scroll thru' menu items to reach SET UP BC Custom
- Press INFO and hold - to display 1st menu item SET UP BC ODO appears
- Press TRIP repeatedly - to scroll thru' menu items. During this the bottom line indicates where the menu item currently appears on the display i.e. top or bottom
- Press INFO once briefly - to change your choice to TOP or BOTTOM
- Press TRIP repeatedly - to reach EXIT menu item
- Press TRIP and hold - BC CUSTOM will appear
- Press TRIP and hold again
- Press TRIP repeatedly - to position your choice at the TOP (in my case RANGE to empty)
- Press INFO repeatedly - to position your choice at the BOTTOM (in my case SPEED actual)