Except for the small ones for the homebuilt or RC communities, nothing new is being designed. Turbines killed the radial engine long ago. They leak oil mostly from period when manufactured. That and oil was cheap. Modern overhauls of most radials have pretty acceptable consumption. Sitting, they still have lower cylinder drain back concerns, but that is just operating a radial.
Reminds me of my Jeep, "It's not leaking, it's just marking its territory."
Radials once were the best way to get adequate cooling in large displacement piston engines without going to the complications of liquid cooling, at the cost of aerodynamic drag and mechanical complexity. Nowadays, turbine engines have all but completely taken over the high power applications, so radials are mostly relegated to nostalgia applications, with no real technological advances.