The more heat that is produced, the more fuel you need to cool the cylinder. So, not having an IC that is going to cool down BAT's will require more fuel than a system that is properly cooled.
HPFP and and new in tank will take care of the fueling issue. The car has barely started to ramp up in support. To me, this is the new EvoX. You will see this car ripping up the track in the next couple years.