I think its all about keeping the brake temp on optimum level inside the operation window (Ceramic brakes are very Temp sensitive, due high efficiency on high operational temperatures, about 650 - 850, max 1400 °C). And from that reason because teams pretty well understand the behavior of C-Si brakes they adapt and opt the brakes during season more often. They made such adaptations by changing quantity of air inlet volume (
altering the shape of brake ducts) or like is very common in Ferrari case play with shape of cooling disk.
From that fact + if you add in equation "scoppless duct design" you could quickly figure out the main goal of Ferrari engineers behind it.
So in my opinion Ferrari aero experts prime goal is to keep the shape of inside flow around the tire (so known tire wake) intact, unchanged as possible, they probably don't want to mess with it to much by different shapes of the scoops. That os probably cus they will hurt aero on the car to much. This aproach is convenient expecialy if you really have issues about knowledge and understanding of windunnel results=>bad correlation bv. really nice article about it
LINK 3
In other words Spa is low demanding braking circuit according BREMBO drivers there keep the brake pedal down for about 11% of lap time with only 2 hard braking spots. (sources
LINK 1,
LINK 2)
And Brembo engineers find solution for Ferrari. They y simply reduce the total heat transfer and radiation area inside disk.0
SOME reading LINKS about BRAKES
LINK 4,
LINK 5,
LINK 6,
LINK 7
EDIT: add link in about duct shape design, correct some word
"And if you no longer go for a gap that exists, you're no longer a racing driver..." Ayrton Senna