Minimum cranking voltage is probably around 10VDC. FI cut off voltage is may be around 9VDC.
Starter motor demand more juice to crank. If the battery is weak, I would want every juice got to FI while kick start the engine if so equipped.
When my PGFI equipped Civic's battery was weak, the starter motor was not cranking. Engine didn't start. But I was able to push start the engine alone and get home safely.
Having kick-start is like having an insurance to me, especially, you can not push start scooters.