Despite the high compression, I have no problem hot starting the 195 hp IO-360 in my RV-6, but your post reminded me of a mid-wing Extra 300 I used to fly a lot. We used it for advanced spin courses, high performance aerobatic training, and competition coaching/prep, so the plane got a lot of use and often it would only be on the ground for maybe 45 minutes before we'd be starting it up again.
That AEIO-540 was tough to hot start, so after shutdown we'd put a high speed 20" cage fan on the ground underneath the engine and open the oil door. as soon as it was rolled back into the hangar. You could see the hot air venting through the air inlets and oil door.
It didn't lower the oil temp as much as you might expect, but it did make hot starting much easier. Without it -- say, when we were at an aerobatic competition -- that engine would vapor lock in the worst way.
The only other airplane I ever really had a tough time hot starting was an SR-20, but eventually that was traced to some seriously mis-timed magnetos.
--Ron