Excellent post Hoistop.
It's 20 years since I was last involved/doing Lynx PPI and Max con checks.
Engine performance checks to keep matters simple.
Memory says that in the early days of Lynx, the first Twin for Teeny Weeny Airways, many Engineers got off on the wrong foot.
Some folk myself included where never happy about 'Destroying Power' from a good engine, Basic Engineering training.
The two engines had to be balance to within a 'Couple of %' of each other and it took time and experience to be easy about reducing the power of the higher engine and bringing it down to the output of the "Worst' engine.
Still it became all straight forward when basic matters had been explained and PPI where Normally done on a return flt to base by Experienced aircrew saving a Formal Air test.
john
Nice to see this Old Bug Bear is still confusing the yooff of taday.