Hello Skee!
Being a newcomer to Recr. Fl. I have not yet had the possibility to explore every corner of it, nor to be acquainted to all the tips and tricks. But this is indeed interesting reading to me, as I made an emergency landing on a rough grassfield in Southern Poland this Wednesday with my factory build Savannah. Burned a hole in a piston of the right hand rear cylinder (for the 2. time in 4 years by the way).
Every expert knowing much more about engine cooling than I do have always stressed the primary importance of getting the air OUT of the engine bay, this matters much more than the size of the air intakes. In the best case you could perhaps at a later stage reduce the size of those big air intakes if you manage to optimize the size and/or position and/or angle of the oblique downward-rearward pointing cowlflap at the lower-rear end of the cowl.
We can't take it for granted that the default ICP-positioning of that cowlflap is quite optimal, I think my story indicates that. OK, it was a Jabiru, but still!
Optimizing the air-suction by Venturi-effect was the lesson I should have learned before burning a piston for the 2. time!
So, I am also looking for a liquid-cooled engine, and the D-motor seems perfect. Wonder how many UL-pilots in Europe have any experience with it??
Kind regards and good luck