According to Subaru motorsport magazine column,
-GTA had issued a special bulletin allowing the louver and lip in the body opening to JAF-GT cars as a measure against heat for summer race (Thailand, Fuji, Autopolis, SUGO).
1)You can add louver or lip up to 50 mm high to the (bonnet) opening for heat dissipation.
2)The engine cannot be seen from above, but it can be seen up to 50% only in summer.
https://www.subaru-msm.com/2019/sgt/column/2