Well everyone has leaning problems for a start. You may be an academic but can you true a screw driver generally no. I know off a very clever fella that once fixed his 210 in to a 182 buy glueing his u/c handle into the down position or one friend that I will assure you all that make you like a primary school kids but put a nut on and his lost.
Where is the data that these are failing at are they 1st life, like ive said cly failure on general don't happen on a 1 st life engine OEM and separation happens at the end of the screw thread.
Now this also proves that it is a between the inter fit and the screw thread that hold the head on. With out either that don't stay on. Manufacture's wont do unnecessary work like fit a screw thread for know other reason. Also there is nearly always a sign before separation, you need to know the signs.
Why did we never use R1340 engines cause when they have a head separation the engine stops and in a R985 the engine looses performance and allows you to get back. We never had a head separation because we always always always checked during the day on shut down and ever night on return to base.
So why do you think that FAA wont these cly out of service.
And why don't I have a problem because I check recheck and check again that's why im good at my job. That's why im get ask all the time what im doing , that's why im sent all over the place to work.
Cheers