Toodogs,
The Australian report is a very poor proof that leaning LOP is bad, on the contrary; in most POH's you will find that 'leaning to best economy' as mentioned in the report is 25°F ROP.
Now I completely agree that 25°F ROP is too rich or way too lean, go to 25°F LOP or 100°F ROP and then you're safe. During climb and cruise CHT and smoothness must be observed, I keep CHT below 380°F at all times. On turbocharged engines TIT will also be a limit.
GAMI is providing the Australian CAA with updated engine data, a Navajo engine is running on their test stand following this accident.
On the other hand, it is wrong to blame all current TCM and Lycoming QC problems on pilot leaning techniques. One of my friends just had major problems after 200 hours since new cylinders with TCM valve wobble, on a turbocharged TSIO-360. immediately fingers were pointing to his LOP flying, forgetting that valve wobble is caused by improper centering of the valve guides during installation, no pilot action could have caused this.
Leaning beyond peak is safe and proper operation, if engine runs smoothly and temperatures are monitored. In fact LOP temperatures will mostly be lower than for a similar horsepower output ROP.
I pay for my own engines and fuel.