Crazy stuff
Autorotations to the ground, if taught properly at ab-initio and practiced annually, at least biennually are NOT a perishable skill. If a pilot perishes his skill so quickly that it is noticeable at this frequency, then he should not be a pilot and would demonstrate it at his annual check.
I agree that;
1) chopping a throttle without reason may lead to an unexpected engine stop,
2) putting the sprag clutch, or freewheel, to excess use would be in contravention of the normal expected usage, and therefore could be hazardous, I.E. lead to a before than usual TBO failure.
3) shock cooling of cylinders leads to top end failures (of the cylinder)
4) sudden and sustained reductions in power will lead to shock cooling of cylinders.
tet