Not sure about the integrity changing by cutting it. Perhaps the primary purpose of the center bar is to support two 24" hoods.
The output of the LEDs on the Finnex fixture have some spread so the area under the bar won't be completely shadowed. Assuming you don't have the Finnex fixture yet, if you can hold a 48" shop light over the tank in a darkened room, then you can see the shadowing effects of the center bar.