None of these two stroke diesels seems to be going anywhere in the last 15-20 years. Deltahawk has been “just around the corner” for decades. They do appear to be certified a few days ago. which is a bit odd since they are targeting the experimental market.
I like the concept of the Zoche better. Aircooling should be lighter and more robust than watercooled. A radial with even number of cylinders is a bit odd, though (pun intended).
A pity it does not seem to be going anywhere