I don't know anything about the Jabaru in a Kitfox but I have a hanger neighbor that has the 3300 in a Zenith 601XL.

He has to watch his temperature a lot. He has told me that the prop he is using does not move enough air into the cooling vanes on the engine. Supposedly there is limited air flow into the engine near the propellor hub.

I understand there are some props that move more air near the hub than some others.

When I was at Arlington one year I spoke to the Jabaru dealer there and he mentioned the specific need to have enough air flowing over the engine and that some props were better than others. I don't remember which props he suggested. As I recall he also named some that were bad actors when it comes to moving air at the hub.