This is from the manual:
It does not seem to address your point exactly but the last line indicates that the starter switch is turned off after the engine is stopped with engine kill knob.
But since they don't make a fuss about it either way and it has worked both ways for you maybe it doesn't matter much.
1) Stopping procedure
1a) Place the clutch handle in the "neutral" position and
idle the engine for about 5 minutes.
If the engine is stopped suddenly
while at a high temperature, the temperature
of various parts will increase.
This may result in engine trouble.
After five minutes' idling, place the speed control lever
in the "full" position and raise the rpms to about 3600 to
blow out any burnt gas in the cylinder.
Set the engine to the lowest speed (about 850-900 rpm), cut the fuel, and stop the engine.
1. Engine stops if knob is pulled
2. Engine stop cable
Do not stop the engine with the decompression lever. If the decompression
lever used to stop the engine, fuel will spray out and accumulate on top of
the pistons. This will create the danger of an explosion the next time the
engine is started.
2) Be sure to close the kingston **** after stopping.
3) Drain out the cooling water. In winter and in periods of col
d weather when there is the possibility that the cooling water may freeze, the cooling water
should be drained out after use.
Open up the cylinder body side **** located below the intake silencer and drain out the water
in the cylinder.
Open up the **** in the lower part of the exhaust manifold and drain the water from the
manifold. (for 3GMD, 3HM)
Turn the crankshaft 2-3 times by starter motor to remove any water remaining in the cooling
4) While the engine is still warm, wipe off any dirt and grime that has accumulated.
5) Turn off the battery switch.
When stopping the engine with the starter switch "ON", the tube oil pressure warning buzzer
will sound. This does not indicate engine trouble.