More thoughts...
Accidentally switching off and on is not only ugly for transmission, it often results in an exhaust system like a peeled banana due to igniting unburned fuel in the muffler.
Idle check may be gone because rapid RPM changes upset the internals of the engine (crank twisting and upset balance).
Another odd one my CFI told me about... a recommendation to switch on governor at 82% RPM. This procedure avoids accidental flying without governor, but causes a slight overspeed (tried it this morning, under adult supervision).
------------------
More volts, Igor