What I'm getting at is a true "full race" engine would be too much of a product support headache for these companies and the money just isn't there for the competitors. They could provide valve timing, spring pressures, etc. that require frequent valve spring changes, lifter wear, rocker arm damage, etc. IOW, engines that require full internal inspection and routine parts replacement between rounds.
Engines that are purposefully set on KILL for a type of flying [straight line speed runs] that hardly exists. If there was big interest in seeing what these engines could do in a German Speed Cup format, then there would be aftermarket tinkerers selling specialty upgrades like what you see in full scale auto sports.