One small difference I see with the 8FG timers is that the 4th timer is now limited to model timer function, which is what I use that one for on my 9C anyway.
Now, why the two count up/down timers
. Good point. E-sailplane folks can use one timer for total elapsed flight timing. I use the switch I assign as a throttle lock to control this timer, The second timer is to keep track of the motor on climb time ( I never fly to LVC on electrics), you can assign that timer to the throttle stick, at least with a Futaba you can